ß

For the first time, the (d,^{2}He) reaction was successfully used in inverse kinematics to extract the Gamow-Teller transition strength in the ß^{+} direction from an unstable nucleus. The new technique was made possible by the use of an active-target time-projection chamber and a magnetic spectrometer, and opens a path to addressing a range of scientific challenges, including in astrophysics and neutrino physics. In this Letter, the nucleus studied was ^{14}O, and the Gamow-Teller transition strength to ^{14}N was extracted up to an excitation energy of 22 MeV. The data were compared to shell-model and state-of-the-art coupled-cluster calculations. Shell-model calculations reproduce the measured Gamow-Teller strength distribution up to about 15 MeV reasonably well, after the application of a phenomenological quenching factor. In a significant step forward to better understand this quenching, the coupled-cluster calculation reproduces the full strength distribution well without such quenching, owing to the large model space, the inclusion of strong correlations, and the coupling of the weak interaction to two nucleons through two-body currents.

Design and construction of a novel energy-loss optical scintillation system (ELOSS) for heavy-ion particle identification.

We present the development of a novel heavy-ion particle-identification (PID) device based on an energy-loss measurement to be implemented in the focal plane of the S800 spectrograph of the Facility for Rare Isotope Beams (FRIB). The new instrument consists of a multi-segmented optical detector [energy-loss optical scintillation system (ELOSS)] that is filled with xenon at pressures ranging from 400 to 800 Torr. The gas volume is surrounded by arrays of photomultiplier tubes and placed along the direction of the beam for recording the prompt scintillation light. The number of detected photons, which is proportional to the energy deposited by the beam particle along its track in the detector volume, allows one to identify the corresponding atomic number (Z). The ELOSS technology is expected to provide high-resolution ΔE measurements (≤0.6% σ) at a high counting rate (>50 kHz). In addition, it has the capability of providing timing information with around 150 ps resolution (σ) compared to the lack of useable timing information of the conventional ionization chamber relying on drifting charges. The development of fast, accurate ΔE measurement techniques for present and future nuclear science facilities will have a high impact on the design and implementation of rare-isotope beam experiments at FRIB and their scientific outcome. As such, ELOSS also represents a prototype for the development of PID detector systems of other planned and future spectrometers, such as the high rigidity spectrometer at FRIB.

Evidence of a Near-Threshold Resonance in

A narrow near-threshold proton-emitting resonance (E_{x}=11.4 MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4 keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the ß-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11 keV) emission channels.

Constraining the

The ^{30}P(p,γ)^{31}S reaction plays an important role in understanding the nucleosynthesis of A≥30 nuclides in oxygen-neon novae. The Gaseous Detector with Germanium Tagging was used to measure ^{31}Cl ß-delayed proton decay through the key J^{π}=3/2^{+}, 260-keV resonance. The intensity I_{ßp}^{260}=8.3_{-0.9}^{+1.2}×10^{-6} represents the weakest ß-delayed, charged-particle emission ever measured below 400 keV, resulting in a proton branching ratio of Γ_{p}/Γ=2.5_{-0.3}^{+0.4}×10^{-4}. By combining this measurement with shell-model calculations for Γ_{γ} and past work on other resonances, the total ^{30}P(p,γ)^{31}S rate has been determined with reduced uncertainty. The new rate has been used in hydrodynamic simulations to model the composition of nova ejecta, leading to a concrete prediction of ^{30}Si:^{28}Si excesses in presolar nova grains and the calibration of nuclear thermometers.

Design of a custom-made device for real-time optical measurement of differential mineral concentrations in three-dimensional scaffolds for bone tissue engineering.

Monitoring bone tissue engineered (TEed) constructs during their maturation is important to ensure the quality of applied protocols. Several destructive, mainly histochemical, methods are conventionally used to this aim, requiring the sacrifice of the investigated samples. This implies (i) to plan several scaffold replicates, (ii) expensive and time consuming procedures and (iii) to infer the maturity level of a given tissue construct from a cognate replica. To solve these issues, non-destructive techniques such as light spectroscopy-based methods have been reported to be useful. Here, a miniaturized and inexpensive custom-made spectrometer device is proposed to enable the non-destructive analysis of hydrogel scaffolds. Testing involved samples with a differential amount of calcium salt. When compared to a reference standard device, this custom-made spectrometer demonstrates the ability to perform measurements without requiring elaborate sample preparation and/or a complex instrumentation. This preliminary study shows the feasibility of light spectroscopy-based methods as useful for the non-destructive analysis of TEed constructs. Based on these results, this custom-made spectrometer device appears as a useful option to perform real-time/in-line analysis. Finally, this device can be considered as a component that can be easily integrated on board of recently prototyped bioreactor systems, for the monitoring of TEed constructs during their conditioning.

Beam particle identification and tagging of incompletely stripped heavy beams with HEIST.

A challenge preventing successful inverse kinematics measurements with heavy nuclei that are not fully stripped is identifying and tagging the beam particles. For this purpose, the HEavy ISotope Tagger (HEIST) has been developed. HEIST utilizes two micro-channel plate timing detectors to measure the time-of-flight, a multi-sampling ion chamber to measure energy loss, and a high-purity germanium detector to identify isomer decays and calibrate the isotope identification system. HEIST has successfully identified 198Pb and other nearby nuclei at energies of about 75 MeV/A. In the experiment discussed, a typical cut containing 89% of all 198Pb80+ in the beam had a purity of 86%. We examine the issues of charge state contamination. The observed charge state populations of these ions are presented and, using an adjusted beam energy, are well described by the charge state model GLOBAL.

Development and validation of an in-silico tool for the study of therapeutic agents in 3D cell cultures.

Computational models constitute a fundamental asset for cancer research and drug R&D, as they provide controlled environments for testing of hypotheses and are characterized by the total knowledge of the system. These features are particularly useful for 3D cell culture models where a complex interaction among cells and their environments ensues. In this work, we present a programmable simulator capable of reproducing the behavior of cells cultured in 3D scaffolds and their response to pharmacological treatment. This system will be shown to be able to accurately describe the temporal evolution of the density of a population of MDA-MB-231 cells following their treatment with different concentrations of doxorubicin, together with a newly described drug-resistance mechanism and potential re-sensitization strategy. An extensive technical description of this model will be coupled to its experimental validation and to an analysis aimed at identifying which variables and behaviors account for differences in the response to treatment. Comprehensively, this work contributes to the growing field of integrated in-silico/in-vitro analysis of biological processes which has great potential for both the increase of our scientific knowledge and the development of novel, more effective treatments.

First Direct Measurement of

Type-I x-ray bursts can reveal the properties of an accreting neutron star system when compared with astrophysics model calculations. However, model results are sensitive to a handful of uncertain nuclear reaction rates, such as ^{22}Mg(α,p). We report the first direct measurement of ^{22}Mg(α,p), performed with the Active Target Time Projection Chamber. The corresponding astrophysical reaction rate is orders of magnitude larger than determined from a previous indirect measurement in a broad temperature range. Our new measurement suggests a less-compact neutron star in the source GS1826-24.

Erratum: Direct Observation of Proton Emission in

This corrects the article DOI: 10.1103/PhysRevLett.123.082501.

Direct Observation of Proton Emission in

The elusive ß^{-}p^{+} decay was observed in ^{11}Be by directly measuring the emitted protons and their energy distribution for the first time with the prototype Active Target Time Projection Chamber in an experiment performed at ISAC-TRIUMF. The measured ß^{-}p^{+} branching ratio is orders of magnitude larger than any previous theoretical model predicted. This can be explained by the presence of a narrow resonance in ^{11}B above the proton separation energy.

Multi-layer thick gas electron multiplier (M-THGEM): A new MPGD structure for high-gain operation at low-pressure.

The operating principle and performances of the Multi-layer Thick Gaseous Electron Multiplier (M-THGEM) are presented. The M-THGEM is a novel hole-type gaseous electron multiplier produced by multi-layer printed circuit board technology; it consists of a densely perforated assembly of multiple insulating substrate sheets (e.g., FR-4), sandwiched between thin metallic-electrode layers. The electron avalanche processes occur along the successive multiplication stages within the M-THGEM holes, under the action of strong dipole fields resulting from the application of suitable potential differences between the electrodes. The present work focuses on the investigation of two different geometries: a two-layer M-THGEM (either as single or double-cascade detector) and a single three-layer M-THGEM element, tested in various low-pressure He-based gas mixtures. The intrinsically robust confinement of the avalanche volume within the M-THGEM holes provides an efficient reduction of the photon-induced secondary effects, resulting in a high-gain operation over a broad pressure range, even in pure elemental gas. The operational principle, main properties (maximum achievable gain, long-term stability, energy resolution, etc.) under different irradiation conditions, as well as capabilities and potential applications are presented and discussed.

Effect of electrical water bath stunning on physical reflexes of broilers: evaluation of stunning efficacy under field conditions.

The effects of different amounts and frequencies of stunning sine wave alternating current were investigated under field conditions. Seven hundred and fifty broilers were stunned in an electrical water bath with an average root mean square (RMS) current of 150, 200, and 250 mA and frequencies of 200, 400, 600, 800, and 1,200 Hz. The occurrence of corneal reflex, spontaneous eye blinking, and a positive response to a painful stimulus were monitored and recorded immediately after the stunning and at 20 s post-stun. Statistical analysis showed that the electrical stunning frequency (P=0.0004), the stunning RMS current (P<0.0001) and the interaction between stunning frequency and stunning current (P<0.0001) had a significant effect on the occurrence of animals experiencing an abolition of corneal reflex at 20 s post-stun.At a current of 150 mA, the probability of a successful stun was over 90% at 200 Hz, approximately 40% at 400 Hz, and below 5% for frequencies greater than 600 Hz. So, stunning at frequencies greater than 600 Hz cannot be recommended when a RMS current of 150 mA is applied. The maximum probability of a successful stun was obtained for a current level of 200 mA at 400 Hz and for a current level of 250 mA at 400 and 600 Hz, whereas the stunning treatments at 1,200 Hz provided the lowest probability of a successful stun. Assessment of spontaneous eye blinking and responses to comb pinching confirmed the indications coming from the analysis of corneal reflex.

A novel fast-neutron detector concept for energy-selective imaging and imaging spectroscopy.

We present and discuss the operational principle of a new fast-neutron detector concept suitable for either energy-selective imaging or for imaging spectroscopy. The detector is comprised of a series of energy-selective stacks of converter foils immersed in a noble-gas based mixture, coupled to a position-sensitive charge readout. Each foil in the various stacks is made of two layers of different thicknesses, fastened together: a hydrogen-rich (plastic) layer for neutron-to-proton conversion, and a hydrogen-free coating to selectively stop/absorb the recoil protons below a certain energy cut-off. The neutron-induced recoil protons, that escape the converter foils, release ionization electrons in the gas gaps between consecutive foils. The electrons are then drifted towards and localized by a position-sensitive charge amplification and readout stage. Comparison of the images detected by stacks with different energy cut-offs allows energy-selective imaging. Neutron energy spectrometry is realized by analyzing the responses of a sufficient large number of stacks of different energy response and unfolding techniques. In this paper, we present the results of computer simulation studies and discuss the expected performance of the new detector concept. Potential applications in various fields are also briefly discussed, in particularly, the application of energy-selective fast-neutron imaging for nuclear safeguards application, with the aim of determining the plutonium content in Mixed Oxide (MOX) fuels.

High-frame rate imaging of two-phase flow in a thin rectangular channel using fast neutrons.

We have demonstrated the feasibility of performing high-frame-rate, fast neutron radiography of air-water two-phase flows in a thin channel with rectangular cross section. The experiments have been carried out at the accelerator facility of the Physikalisch-Technische Bundesanstalt. A polychromatic, high-intensity fast neutron beam with average energy of 6 MeV was produced by 11.5 MeV deuterons hitting a thick Be target. Image sequences down to 10 ms exposure times were obtained using a fast-neutron imaging detector developed in the context of fast-neutron resonance imaging. Different two-phase flow regimes such as bubbly slug and churn flows have been examined. Two phase flow parameters like the volumetric gas fraction, bubble size and mean bubble velocities have been measured. The first results are promising, improvements for future experiments are also discussed.

Myoelectrically driven functional electrical stimulation may increase motor recovery of upper limb in poststroke subjects: a randomized controlled pilot study.

The objective of this randomized controlled pilot study was to assess the feasibility and effectiveness of myoelectrically controlled functional electrical stimulation (MeCFES) for rehabilitation of the upper limb in poststroke subjects. Eleven poststroke hemiparetic subjects with residual proximal control of the arm, but impaired volitional opening of the paretic hand, were enrolled and randomized into a treated and a control group. Subjects received 3 to 5 treatment sessions per week until totaling 25 sessions. In the experimental group, myoelectric activity from wrist and finger extensors was used to control stimulation of the same muscles. Patients treated with MeCFES (n = 5) had a significant (p = 0.04) and clinically important improvement in Action Research Arm Test score (median change 9 points), confirmed by an Individually Prioritized Problem Assessment self-evaluation score. This improvement was maintained at follow-up. The control group did not show a significant improvement (p = 0.13). The reduced sample size of participants, together with confounding factors such as spontaneous recovery, calls for larger studies to draw definite conclusions. However, the large and persistent treatment effect seen in our results indicate that MeCFES could play an important role as a clinical tool for stroke rehabilitation.

Development of a cold-neutron imaging detector based on thick gaseous electron multiplier.

We present the results of our recent studies on a cold-neutron imaging detector prototype based on THick Gaseous Electron Multiplier (THGEM). The detector consists of a thin Boron layer, for neutron-to-charged particle conversion, coupled to two THGEM electrodes in cascade for charge amplification and a position-sensitive charge-readout anode. The detector operates in Ne∕(5%)CF4, at atmospheric pressure, in a stable condition at a gain of around 10(4). Due to the geometrical structure of the detector elements (THGEM geometry and charge read-out anode), the image of detector active area shows a large inhomogeneity, corrected using a dedicated flat-filed correction algorithm. The prototype provides a detection efficiency of 5% and an effective spatial resolution of the order of 1.3 mm.

Fast bedside measurement of blood count and C-reactive protein in newborns compared with conventional methods.

BACKGROUND: Abnormal complete blood count (CBC) and high plasma C-reactive protein (CRP) are associated with neonatal infections and could be helpful in the diagnosis of neonatal sepsis and to monitor the antibiotic treatment. OBJECTIVES: The aim of this work is to evaluate and compare the performance of a bedside analyzer for blood count and C-reactive protein (CRP) with a conventional analyzer in a neonatal population. METHODS: 150 capillary or venous blood samples of term and preterm newborns were processed on an ABX-MicrosCRP200 analyzer and on a SysmexXE2100 (conventional hematology analyzer) for CBC, leukocyte differential, reticulocytes, and nucleated red blood cells (NRBC); high-sensitivity CRP (hs-CRP) was performed on a ModularPE. The differences between complete blood count and CRP were regressed against their means and assessed by means of intra-class-correlation. RESULTS: The intra-class-correlation for white blood cell (WBC) was 0.98, for hemoglobin 0.97, for hematocrit 0.96, for mean corpuscular volume 0.95, and for platelet 0.98. ABX-MicrosCRP200 overestimated the WBC (+1.27 x 10(3)/microL; p < 0.001), hematocrit (+1.80%; p < 0.001), and platelet (+13.55 x 10(3)/microL; p < 0.001). The intra-class-correlation for CRP was high (0.97), without systematic difference between the two values (p = 0.64). CONCLUSIONS: The agreement between the two methods was high for both tests. However, the SD of the difference for WBC and platelet could be clinically important in leukopenic or thrombocytopenic newborns.

The determinants of performance in master swimmers: a cross-sectional study on the age-related changes in propelling efficiency, hydrodynamic position and energy cost of front crawl.

The decrease in swimming performance (v (max)) that occurs with age is a not only consequence of the physiological decrease in maximal metabolic power ([Formula: see text]) but can also be expected to depend on an increase in the energy cost of swimming (C) [Formula: see text] In turn, for a given speed and stroke C = W (d) / (η(P)η(o)) where W (d) is hydrodynamic resistance, η(P) is propelling efficiency and η(o) is overall efficiency. The aim of this study was to measure C in 47 male masters (31-85 years old) swimming the front crawl at sub-maximal, aerobic, speeds. During the experiments propelling efficiency and projected frontal area (A (eff), an index of W (d)) were also determined by kinematic analysis. "Elder" masters (60-80 years) swam at a significantly slower pace (0.65 vs. 0.91 m s(-1)), with a lower η(P) (0.23 vs. 0.31) and a larger A (eff) (0.39 vs. 0.23 m(2)) than "younger" masters (30-60 years). No significant differences in C (1.45 kJ m(-1), on the average) were observed as a function of age or speed, but C values were significantly higher than those assessed in young elite swimmers at the very same speeds; the difference increasing with age with a rate of 0.75 % per year. With the due considerations (in this study the observed changes in η(P), A (eff) and C can be either attributed to changes in speed or age) these data confirm the hypothesis that an increase in C contributes to the decrease in swimming performance that occurs with age.

PIVKA-II plasma levels as markers of subclinical vitamin K deficiency in term infants.

BACKGROUND: As the vitamin K content of human milk is low and the newborn infant's stores of vitamin K are small, vitamin K deficiency with hemorrhage in the newborn is a worldwide problem. Proteins Induced by Vitamin K Absence (PIVKA-II) are the inactive under-γ-carboxylated forms of vitamin K-dependent clotting factors and they could be useful in predicting subclinical vitamin K deficiency (VKD). OBJECTIVES: To demonstrate that PIVKA-II are earlier markers of subclinical VKD than Prothrombin time (PT) in exclusively breast-fed newborns. METHODS: A prospective, controlled, randomized study, including 53 term newborns receiving vitamin K prophylaxis (0.5 mg i.m.) at birth, was performed. At 30 days newborns were divided into three groups (G) receiving respectively: 25 µg/die of vitamin K (G I), 12 µg/die (G II) or placebo (G III). PIVKA-II and PT were measured on 30th and 90th days of life. RESULTS: G III and GII showed a significant increase in PIVKA-II from 30 to 90 days of life respectively from 2.6 to 4.7 (p = 0.001) and from 2.3 to 3.5 (p < 0.001). No significant changes were found in GI. PT showed no significant changes among groups. CONCLUSIONS: PT is a less sensitive marker than PIVKA II. Oral supplementation with 25 µg/die avoids an increase of PIVKA-II. Despite increased PIVKA-II do not mean an impending occurrence of bleeding, they highlight a subclinical VKD and its relative risk.

New prospective for non-invasive detection, grading, size evaluation, and tumor location of prostate cancer.

BACKGROUND: PSA blood test and other present screening tools fail to provide the required sensitivity and specificity and, at early stages, lack correlation with tumor grade, volume, and location. Thus alternative approaches are highly desired. We present and assess a novel method for PCa detection, grading, volume evaluation and tumor location, based on non-invasive zinc concentration mapping in the gland by means of a dedicated rectal probe. METHODS: Zinc-concentration values measured in histologically examined tissue fragments from needle biopsy of 598 patients were analyzed. They were used to generate computer simulated zinc-concentration maps, further analyzed with image-processing tools. The tumor detection performances versus Gleason grade were assessed. RESULTS: A significant increase of zinc depletion with increasing Gleason pattern (grade) classification was established. Tumor detection performance in zinc-concentration maps progressively improves with the cancer's first component score. Reliable information on the location, size and Gleason-grade combination of the lesion can be extracted for clinically relevant volumes. CONCLUSIONS: Zinc depletion in the prostate peripheral zone is the basis for a novel, non-invasive PCa detection, localization, volume evaluation and grading method. Its realization and application as a pre-biopsy and pre-treatment examination, or a follow-up tool, relies on the development of a dedicated transrectal probe. It should have significant impact on biopsy effectiveness, point at a possible extraprostatic extension and provide critical data for focal treatment. The information on tumor grade and distribution may have an important impact on disease management.