Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, z_{g}, and the (scaled) groomed jet radius, θ_{g}. Charged-particle jets are reconstructed at midrapidity using the anti-k_{T} algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θ_{g} distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the z_{g} distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.

Measurement of Prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrt[s]=13  TeV. This is the first measurement of Σ_{c}^{0,++} production in hadronic collisions. Assuming the same production yield for the three Σ_{c}^{0,+,++} isospin states, the baryon-to-meson cross section ratios Σ_{c}^{0,+,++}/D^{0} and Λ_{c}^{+}/D^{0} are calculated in the transverse momentum (p_{T}) intervals 2<p_{T}<12 and 1<p_{T}<24  GeV/c. Values significantly larger than in e^{+}e^{-} collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σ_{c}. The feed-down contribution to Λ_{c}^{+} production from Σ_{c}^{0,+,++} is also reported and is found to be larger than in e^{+}e^{-} collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.

Measurement of the Cross Sections of Ξ_{c}^{0} and Ξ_{c}^{+} Baryons and of the Branching-Fraction Ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+}) in pp Collisions at sqrt[s]=13 TeV

The p_{T}-differential cross sections of prompt charm-strange baryons Ξ_{c}^{0} and Ξ_{c}^{+} were measured at midrapidity (|y|<0.5) in proton-proton (pp) collisions at a center-of-mass energy sqrt[s]=13  TeV with the ALICE detector at the LHC. The Ξ_{c}^{0} baryon was reconstructed via both the semileptonic decay (Ξ^{-}e^{+}ν_{e}) and the hadronic decay (Ξ^{-}π^{+}) channels. The Ξ_{c}^{+} baryon was reconstructed via the hadronic decay (Ξ^{-}π^{+}π^{+}) channel. The branching-fraction ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+})=1.38±0.14(stat)±0.22(syst) was measured with a total uncertainty reduced by a factor of about 3 with respect to the current world average reported by the Particle Data Group. The transverse momentum (p_{T}) dependence of the Ξ_{c}^{0}- and Ξ_{c}^{+}-baryon production relative to the D^{0} meson and to the Σ_{c}^{0,+,++}- and Λ_{c}^{+}-baryon production are reported. The baryon-to-meson ratio increases toward low p_{T} up to a value of approximately 0.3. The measurements are compared with various models that take different hadronization mechanisms into consideration. The results provide stringent constraints to these theoretical calculations and additional evidence that different processes are involved in charm hadronization in electron-positron (e^{+}e^{-}) and hadronic collisions.

Demonstrating Apparently Inconspicuous but Sensitive Impacts on the Rollover Failure of Lithium-Ion Batteries at a High Voltage

Layered oxides, such as Li[Ni_0.5Co_0.2Mn_0.3]O₂ (NCM523), are promising cathode materials for operation at a high voltage, i.e., high-energy lithium-ion batteries. The instability-reasoned transition metal dissolution remains a major challenge, which initiates electrode cross-talk, alteration of the solid electrolyte interphase, and enhanced Li-metal dendrite formation at the graphite anode, consequently leading to rollover failure. In this work, relevant impacts on this failure mechanism are highlighted. For example, a conventional coating of NCM523 with aluminum oxide as a typical high-voltage modification improves kinetic aspects but can only postpone the rollover failure to later charge/discharge cycles. Interestingly, a similar effect on the rollover failure is observed merely after modification of the cell formation protocol, i.e., the first cycles. Further influences of specific test protocols are highlighted and show that the rollover failure even disappears at C-rates above 2C, which can be attributed to a more homogeneous distribution of Li-metal dendrite formation. It is worth noting that a variation of anode porosity can reveal similar effects, as, e.g., variations in anode processing also impact Li dendrite distribution and the appearance of rollover failure. Overall, the rollover failure is a valid but complex phenomenon, which sensitively depends on apparently inconspicuous parameters and should not be disregarded.

Λ_{c}^{+} Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV at the LHC

The prompt production of the charm baryon Λ_{c}^{+} and the Λ_{c}^{+}/D^{0} production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sqrt[s_{NN}]=5.02  TeV. These new measurements show a clear decrease of the Λ_{c}^{+}/D^{0} ratio with increasing transverse momentum (p_{T}) in both collision systems in the range 2<p_{T}<12  GeV/c, exhibiting similarities with the light-flavor baryon-to-meson ratios p/π and Λ/K_{S}^{0}. At low p_{T}, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e^{+}e^{-} and e^{-}p collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.

Differences Between MR Brain Region Segmentation Methods: Impact on Single-Subject Analysis

For the segmentation of magnetic resonance brain images into anatomical regions, numerous fully automated methods have been proposed and compared to reference segmentations obtained manually. However, systematic differences might exist between the resulting segmentations, depending on the segmentation method and underlying brain atlas. This potentially results in sensitivity differences to disease and can further complicate the comparison of individual patients to normative data. In this study, we aim to answer two research questions: 1) to what extent are methods interchangeable, as long as the same method is being used for computing normative volume distributions and patient-specific volumes? and 2) can different methods be used for computing normative volume distributions and assessing patient-specific volumes? To answer these questions, we compared volumes of six brain regions calculated by five state-of-the-art segmentation methods: Erasmus MC (EMC), FreeSurfer (FS), geodesic information flows (GIF), multi-atlas label propagation with expectation–maximization (MALP-EM), and model-based brain segmentation (MBS). We applied the methods on 988 non-demented (ND) subjects and computed the correlation (PCC-v) and absolute agreement (ICC-v) on the volumes. For most regions, the PCC-v was good (>0.75), indicating that volume differences between methods in ND subjects are mainly due to systematic differences. The ICC-v was generally lower, especially for the smaller regions, indicating that it is essential that the same method is used to generate normative and patient data. To evaluate the impact on single-subject analysis, we also applied the methods to 42 patients with Alzheimer’s disease (AD). In the case where the normative distributions and the patient-specific volumes were calculated by the same method, the patient’s distance to the normative distribution was assessed with the z-score. We determined the diagnostic value of this z-score, which showed to be consistent across methods. The absolute agreement on the AD patients’ z-scores was high for regions of thalamus and putamen. This is encouraging as it indicates that the studied methods are interchangeable for these regions. For regions such as the hippocampus, amygdala, caudate nucleus and accumbens, and globus pallidus, not all method combinations showed a high ICC-z. Whether two methods are indeed interchangeable should be confirmed for the specific application and dataset of interest.

Experimental Evidence for an Attractive p-ϕ Interaction

This Letter presents the first experimental evidence of the attractive strong interaction between a proton and a ϕ meson. The result is obtained from two-particle correlations of combined p-ϕ⊕ p[over ¯]-ϕ pairs measured in high-multiplicity pp collisions at sqrt[s]=13  TeV by the ALICE Collaboration. The spin-averaged scattering length and effective range of the p-ϕ interaction are extracted from the fully corrected correlation function employing the Lednický-Lyuboshits approach. In particular, the imaginary part of the scattering length vanishes within uncertainties, indicating that inelastic processes do not play a prominent role for the p-ϕ interaction. These data demonstrate that the interaction is dominated by elastic p-ϕ scattering. Furthermore, an analysis employing phenomenological Gaussian- and Yukawa-type potentials is conducted. Under the assumption of the latter, the N-ϕ coupling constant is found to be g_{N-ϕ}=0.14±0.03(stat)±0.02(syst). This work provides valuable experimental input to accomplish a self-consistent description of the N-ϕ interaction, which is particularly relevant for the more fundamental studies on partial restoration of chiral symmetry in nuclear medium.

Recurrent inference machines as inverse problem solvers for MR relaxometry

In this paper, we propose the use of Recurrent Inference Machines (RIMs) to perform T₁ and T₂ mapping. The RIM is a neural network framework that learns an iterative inference process based on the signal model, similar to conventional statistical methods for quantitative MRI (QMRI), such as the Maximum Likelihood Estimator (MLE). This framework combines the advantages of both data-driven and model-based methods, and, we hypothesize, is a promising tool for QMRI. Previously, RIMs were used to solve linear inverse reconstruction problems. Here, we show that they can also be used to optimize non-linear problems and estimate relaxometry maps with high precision and accuracy. The developed RIM framework is evaluated in terms of accuracy and precision and compared to an MLE method and an implementation of the Residual Neural Network (ResNet). The results show that the RIM improves the quality of estimates compared to the other techniques in Monte Carlo experiments with simulated data, test-retest analysis of a system phantom, and in-vivo scans. Additionally, inference with the RIM is 150 times faster than the MLE, and robustness to (slight) variations of scanning parameters is demonstrated. Hence, the RIM is a promising and flexible method for QMRI. Coupled with an open-source training data generation tool, it presents a compelling alternative to previous methods.

Multiharmonic Correlations of Different Flow Amplitudes in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

The event-by-event correlations between three flow amplitudes are measured for the first time in Pb-Pb collisions, using higher-order symmetric cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium when compared to correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements since contributions from two-harmonic correlations are explicitly removed in the new observables. A comparison to Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions.

Soft-Dielectron Excess in Proton-Proton Collisions at sqrt[s]=13 TeV

A measurement of dielectron production in proton-proton (pp) collisions at sqrt[s]=13  TeV, recorded with the ALICE detector at the CERN LHC, is presented in this Letter. The data set was recorded with a reduced magnetic solenoid field. This enables the investigation of a kinematic domain at low dielectron (ee) invariant mass m_{ee} and pair transverse momentum p_{T,ee} that was previously inaccessible at the LHC. The cross section for dielectron production is studied as a function of m_{ee}, p_{T,ee}, and event multiplicity dN_{ch}/dη. The expected dielectron rate from hadron decays, called hadronic cocktail, utilizes a parametrization of the measured η/π^{0} ratio in pp and proton-nucleus collisions, assuming that this ratio shows no strong dependence on collision energy at low transverse momentum. Comparison of the measured dielectron yield to the hadronic cocktail at 0.15<m_{ee}<0.6  GeV/c^{2} and for p_{T,ee}<0.4  GeV/c indicates an enhancement of soft dielectrons, reminiscent of the "anomalous" soft-photon and soft-dilepton excess in hadron-hadron collisions reported by several experiments under different experimental conditions. The enhancement factor over the hadronic cocktail amounts to 1.61±0.13(stat)±0.17(syst,data)±0.34(syst,cocktail) in the ALICE acceptance. Acceptance-corrected excess spectra in m_{ee} and p_{T,ee} are extracted and compared with calculations of dielectron production from hadronic bremsstrahlung and thermal radiation within a hadronic many-body approach.

Aspects of transition cow metabolomics-Part I: Effects of a metaphylactic butaphosphan and cyanocobalamin treatment on the metabolome in liver, blood, and urine in cows with different liver metabotypes

Dairy cows in modern production systems are at risk to develop metabolic disorders during the transition period. Reasons for individual differences in susceptibility, as well as the underlying pathomechanisms, are still only partially understood. The development of metaphylactic treatment protocols is needed. In this context, an on-farm prospective 3-fold blinded randomized study involving 80 German Holstein cows was performed throughout 1 yr. The trial involved a thorough recording of the production and clinical traits, clinical chemistry, and liver biopsies and blood and urine sampling at d 14 (mean: 12 d, range: 1-26 d) antepartum (AP), and d 7 (7, 4-13) and 28 (28, 23-34) postpartum (PP) for metabolomics analyses. Two groups received a treatment with butaphosphan and cyanocobalamin (BCC) at either the dosage recommended by the manufacturer or the double dosage (5 or 10 mL/100 kg of body weight 10% butaphosphan and 0.005% cyanocobalamin (Catosal, Bayer Animal Health), n = 20 in each group, parity: 4.2 ± 2.0 and 3.4 ± 1.3, respectively (mean ± SD)] and one group a placebo treatment (NaCl 0.9%, n = 40, parity: 4.0 ± 1.9). The animals were treated at 6 time points (7, 6, and 5 d AP, and 1, 2, and 3 d PP) via intravenous injection. Mass spectroscopy-based targeted metabolomics analysis of blood plasma and liver samples were performed using the AbsoluteIDQ p180 kit (Biocrates Life Sciences), whereas the urine samples were analyzed by nuclear magnetic resonance spectroscopy. Statistical analysis was performed using multivariate [partial least squares discriminant analysis (PLS-DA)] and univariate methods (linear mixed model). Multivariate data analysis (PLS-DA plots) of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in liver metabolome profile between AP and PP status). Metabotype B animals were characterized by higher PP lipomobilization (stronger PP body condition decrease and higher blood bilirubin, fatty acids, gamma-glutamyltransferase, and triglyceride levels) and a higher occurrence of transition cow diseases, compared with the animals in metabotype C. Analysis of the feeding data showed that the period of metabotype B animals (calving in a distinct time frame) was characterized by a decreased grass silage quality. The PP liver metabolome of the metabotype C animals was characterized by higher concentrations of AA, acylcarnitines, lysoPC and sphingomyelins compared with metabotype B. For the metaphylactic treatment with BCC a dose-dependent effect was confirmed, differing between the metabotypes. In all matrices and metabotypes at various time points significant treatment effects were observed, with different profiles in clinical chemistry and as well in metabolomics data. The most clear-cut treatment effect was observed in metabotype B in the liver at 7 d PP, characterized by an increase in several acylcarnitines and phosphatidylcholines, indicating a more efficient influx and oxidation of fatty acids in mitochondria and thereby an increase in energy supply and more efficient triglyceride export in the liver. The results from the liver metabolomics analysis support the application of an indication-based metaphylactic treatment with BCC.

Aspects of transition cow metabolomics-Part III: Alterations in the metabolome of liver and blood throughout the transition period in cows with different liver metabotypes

The liver plays a central role in the postpartum (PP) energy metabolism of the transition dairy cow; however, studies describing the liver metabolome during this period were lacking. The aim of the presented study was therefore to compare the alterations in the liver and blood metabolome of transition dairy cows. For this purpose, an on-farm trial with 80 German Holstein cows (mean lactation number: 3.9; range: 2-9) was performed, with thorough documentation of clinical traits and clinical chemistry, as well as production data. Liver biopsies and blood samples were collected at d 14 (mean: 12 d, range: 1-26 d) antepartum (AP), d 7 (7, 4-13) and 28 (28, 23-34; mean, earliest-latest) PP for targeted mass spectroscopy-based metabolomics analysis using the AbsoluteIDQ p180 kit (Biocrates Life Sciences). Statistical analysis was performed using multivariate (partial least squares discriminant analysis) as well as univariate methods (linear mixed model). Multivariate data analysis of the liver metabolome revealed 3 different metabotypes (A = medium, B = minor, C = large alterations in the liver metabolome profile between AP and PP). In metabotype C, an increase of almost all acylcarnitines, lysophosphatidylcholines (lysoPC), sphingomyelins, and some phosphatidylcholines (PC, mainly at 7 d PP) was observed after calving. In contrast to metabotype C, the clinical data of the metabotype B animals indicated a higher PP lipomobilization and occurrence of transition cow diseases. The liver metabolome profile of these animals most likely mirrors a failure of adaptation to the PP state. This strong occurrence of metabotypes was much less pronounced in the blood metabolome. Additionally, differences in metabolic patterns were observed across the transition period when comparing liver and blood matrices (e.g., in different biogenic amines, acylcarnitines and sphingolipids). In summary, the blood samples at 7 d PP showed lower acylcarnitines and PC, with minor alterations and a heterogeneous pattern in AA, biogenic amines, and sphingomyelins compared with 14 d AP. In contrast to 7 d PP, the blood samples at 28 PP revealed an increase in several AA, lysoPC, PC, and sphingomyelins in comparison to the AP state, irrespective of the metabotype. In the liver biopsies metabotype B differed from metabotype C animals ante partum by following metabolites: higher α aminoadipic acid, lower AA, serotonin, taurine, and symmetric dimethylarginine levels, lower or higher concentrations of certain acylcarnitines (higher: C2, C3, C5, C4:1; lower: C12:1, C14:1-OH, C16:2), and lower lysoPC (a C16:0, C18:0, C20:3, C20:4) and hexose levels. In blood samples, fewer differences were observed, with lower serotonin, acylcarnitine C16:2, lysoPC (a C16:0, C17:0, C18:0 and C18:1), PC aa C38:0, and PC ae C42:2. The results show that the use of only the blood metabolome to assess liver metabolism may be hampered by the fact that blood profiles are influenced by the metabolism of many organs, and metabolomics analysis from liver biopsies is a more suitable method to identify distinct metabotypes. Future studies should investigate the stability and reproducibility of the metabotype and phenotypes observed, and the possible predictive value of the metabolites already differing AP between metabotype B and C.

Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The elliptic flow of electrons from beauty hadron decays at midrapidity (|y|<0.8) is measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The azimuthal distribution of the particles produced in the collisions can be parametrized with a Fourier expansion, in which the second harmonic coefficient represents the elliptic flow, v_{2}. The v_{2} coefficient of electrons from beauty hadron decays is measured for the first time in the transverse momentum (p_{T}) range 1.3-6  GeV/c in the centrality class 30%-50%. The measurement of electrons from beauty-hadron decays exploits their larger mean proper decay length cτ≈500  μm compared to that of charm hadrons and most of the other background sources. The v_{2} of electrons from beauty hadron decays at midrapidity is found to be positive with a significance of 3.75  σ. The results provide insights into the degree of thermalization of beauty quarks in the medium. A model assuming full thermalization of beauty quarks is strongly disfavored by the measurement at high p_{T}, but is in agreement with the results at low p_{T}. Transport models including substantial interactions of beauty quarks with an expanding strongly interacting medium describe the measurement within uncertainties.

Current practice in nutrition after allogeneic hematopoietic stem cell transplantation - Results from a survey among hematopoietic stem cell transplant centers

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is frequently associated with impaired oral intake and malnutrition, which potentially increases morbidity and mortality. Therefore, nutrition is one of the major challenges in the post-transplant period.

METHODS

To document the current clinical approach in nutritional treatment, we designed a questionnaire concerning the current practice in nutrition after alloHSCT and distributed it to German speaking centers performing alloHSCT in Germany, Austria and Switzerland between November 2018 and March 2020. Twenty-eight (39%) of 72 contacted centers completed the survey, 23 from Germany, two from Austria and three from Switzerland, representing 50% of alloHSCT activity within the participating countries in 2018.

RESULTS

All centers reported having nutritional guidelines for patients undergoing alloHSCT, whereby 86% (n = 24) provided a low-microbial diet during the neutropenic phase. The criteria to start parenteral nutrition (PN) directly after alloHSCT seemed to be consistent, 75% (n = 21) of the corresponding centers started PN if the oral nutritional intake or the bodyweight dropped below a certain limit. In the setting of intestinal graft-versus-host disease (GvHD) the current practice appeared to be more heterogenous. About 64% (n = 18) of the centers followed a special diet, added food stepwise modulated by GvHD symptoms, while only four centers regularly stopped oral intake completely (intestinal GvHD grade >1). Half of the centers (54%, n = 15) applied a lactose-free diet, followed by 43% (n = 12) which provided fat- and 18% (n = 5) gluten-free food in patients with intestinal GvHD. Supplementation of micronutrients in acute intestinal GvHD patients was performed by 54% (n = 15) of the centers, whereas vitamin D (89%, n = 25) and vitamin B₁₂ (68%, n = 19) was added regularly independently of the presence of GvHD. Only 5 (18%) participating centers ever observed a food-associated infection during hospitalization, whereas food-associated infections were reported to occur more often in the outpatient setting (64%, n = 18).

CONCLUSION

The survey documented a general consensus about the need for nutritional guidelines for patients undergoing alloHSCT. However, the nutritional treatment in clinical practice (i.e. lactose-, gluten- or fat-free in intestinal GvHD) as well as the use of food supplements was very heterogeneous. In line with current general recommendations the centers seemed to focus on safe food handling practice rather than providing a strict neutropenic diet. More high-quality data are required to provide evidence-based nutrition to patients during and after alloHSCT.

Registration of magnetic resonance and computed tomography images in patients with oral squamous cell carcinoma for three-dimensional virtual planning of mandibular resection and reconstruction

The aim of this study was to evaluate and present an automated method for registration of magnetic resonance imaging (MRI) and computed tomography (CT) or cone beam CT (CBCT) images of the mandibular region for patients with oral squamous cell carcinoma (OSCC). Registered MRI and (CB)CT could facilitate the three-dimensional virtual planning of surgical guides employed for resection and reconstruction in patients with OSCC with mandibular invasion. MRI and (CB)CT images were collected retrospectively from 19 patients. MRI images were aligned with (CB)CT images employing a rigid registration approach (stage 1), a rigid registration approach using a mandibular mask (stage 2), and two non-rigid registration approaches (stage 3). Registration accuracy was quantified by the mean target registration error (mTRE), calculated over a set of landmarks annotated by two observers. Stage 2 achieved the best registration result, with an mTRE of 2.5±0.7mm, which was comparable to the inter- and intra-observer variabilities of landmark placement in MRI. Stage 2 was significantly better aligned compared to all approaches in stage 3. In conclusion, this study demonstrated that rigid registration with the use of a mask is an appropriate image registration method for aligning MRI and (CB)CT images of the mandibular region in patients with OSCC.

From commodity to money: The rise of silver coinage around the Ancient Mediterranean (sixth-first centuries bce)

The reasons why the Western Mediterranean, especially Carthage and Rome, resisted monetization relative to the Eastern Mediterranean are still unclear. We address this question by combining lead (Pb) and silver (Ag) isotope abundances in silver coinage from the Aegean, Magna Graecia, Carthage and Roman Republic. The clear relationships observed between 109Ag/107Ag and 208Pb/206Pb reflect the mixing of silver ores or silver objects with Pb metal used for cupellation. The combined analysis of Ag and Pb isotopes reveals important information about the technology of smelting. The Greek world extracted Ag and Pb from associated ores, whereas, on the Iberian Peninsula, Carthaginians and Republican-era Romans applied Phoenician cupellation techniques and added exotic Pb to Pb-poor Ag ores. Massive Ag recupellation is observed in Rome during the Second Punic War. After defeating the Carthaginians and the Macedonians in the late second century bce, the Romans brought together the efficient, millennium-old techniques of silver extraction of the Phoenicians, who considered this metal a simple commodity, with the monetization of the economy introduced by the Greeks.

Exploiting the Degradation Mechanism of NCM523 || Graphite Lithium-Ion Full Cells Operated at High Voltage

Invited for this month's cover is the group of Tobias Placke and Martin Winter at the MEET Battery Research Center (University of Münster). The image shows the failure mechanism of high-voltage operated NCM523 || graphite lithium-ion cells, that is, the dissolution of transition metals (Mn, Co, Ni) from the NCM523 cathode and subsequent deposition at the graphite anode, resulting in formation of Li metal dendrites. The Full Paper itself is available at 10.1002/cssc.202002113.

Exploiting the Degradation Mechanism of NCM523 ∥ Graphite Lithium-Ion Full Cells Operated at High Voltage

Layered oxides, particularly including Li[Nix Coy Mnz ]O2 (NCMxyz) materials, such as NCM523, are the most promising cathode materials for high-energy lithium-ion batteries (LIBs). One major strategy to increase the energy density of LIBs is to expand the cell voltage (>4.3 V). However, high-voltage NCM ∥ graphite full cells typically suffer from drastic capacity fading, often referred to as "rollover" failure. In this study, the underlying degradation mechanisms responsible for failure of NCM523 ∥ graphite full cells operated at 4.5 V are unraveled by a comprehensive study including the variation of different electrode and cell parameters. It is found that the "rollover" failure after around 50 cycles can be attributed to severe solid electrolyte interphase growth, owing to formation of thick deposits at the graphite anode surface through deposition of transition metals migrating from the cathode to the anode. These deposits induce the formation of Li metal dendrites, which, in the worst cases, result in a "rollover" failure owing to the generation of (micro-) short circuits. Finally, approaches to overcome this dramatic failure mechanism are presented, for example, by use of single-crystal NCM523 materials, showing no "rollover" failure even after 200 cycles. The suppression of cross-talk phenomena in high-voltage LIB cells is of utmost importance for achieving high cycling stability.

Measurement of the Low-Energy Antideuteron Inelastic Cross Section

In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of 0.3≤p<4  GeV/c. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sqrt[s_{NN}]=5.02  TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the geant4 toolkit for the propagation of (anti)particles through the detector material. The analysis of the raw primary (anti)proton spectra serves as a benchmark for this study, since their hadronic interaction cross sections are well constrained experimentally. The first measurement of the inelastic cross section for antideuteron-nucleus interactions averaged over the ALICE detector material with atomic mass numbers ⟨A⟩=17.4 and 31.8 is obtained. The measured inelastic cross section points to a possible excess with respect to the Glauber model parametrization used in geant4 in the lowest momentum interval of 0.3≤p<0.47  GeV/c up to a factor 2.1. This result is relevant for the understanding of antimatter propagation and the contributions to antinuclei production from cosmic ray interactions within the interstellar medium. In addition, the momentum range covered by this measurement is of particular importance to evaluate signal predictions for indirect dark-matter searches.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2  GeV/c and 3<p_{T}<6  GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions

The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2  GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.

Adverse events during nursing care procedure in intensive care unit: The PREVENIR study

OBJECTIVES

Intensive care unit patients undergo several nursing care procedures (NCP) every day. These procedures involve a risk for adverse events (AE). Yet, their prevalence, intensity, and predisposing risk factors remain poorly established. The main objective of the study was to measure the incidence and severity of NCP related AE.

DESIGN

This prospective observational multicentre study was conducted in 9 ICUs. All NCP were recorded for four consecutive weeks. For each NCP, the following were collected: patients' baseline characteristics, type of NCP, characteristics of the NCP, AE and therapeutic responses.

RESULTS

5849 NCP occurred in 340 patients. Among the 340 patients included, 292 (85.9%) were affected by at least one AE, and 141 (41.5%) by an SAE during a NCP. Thirty % of NCP were associated with at least one AE: hemodynamic AE in 17.1%, respiratory AE in 13.6%, agitation and pain (3.7% and 3.3%). Eight invasive devices were accidentally removed. Severe Adverse Events (SAE) occurred in 5.5% of NCP. The main risk factor associated with SAE was pain/agitation at the beginning of the NCP.

CONCLUSION

AE are frequent during NCP in ICU. We identified several risk factors, some of them preventable, that could be considered for the development of recommendations for the nursing care of critically ill patients.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02881645.

Radiomics approach to distinguish between well differentiated liposarcomas and lipomas on MRI

Background

Well differentiated liposarcoma (WDLPS) can be difficult to distinguish from lipoma. Currently, this distinction is made by testing for MDM2 amplification, which requires a biopsy. The aim of this study was to develop a noninvasive method to predict MDM2 amplification status using radiomics features derived from MRI.

Methods

Patients with an MDM2‐negative lipoma or MDM2‐positive WDLPS and a pretreatment T1‐weighted MRI scan who were referred to Erasmus MC between 2009 and 2018 were included. When available, other MRI sequences were included in the radiomics analysis. Features describing intensity, shape and texture were extracted from the tumour region. Classification was performed using various machine learning approaches. Evaluation was performed through a 100 times random‐split cross‐validation. The performance of the models was compared with the performance of three expert radiologists.

Results

The data set included 116 tumours (58 patients with lipoma, 58 with WDLPS) and originated from 41 different MRI scanners, resulting in wide heterogeneity in imaging hardware and acquisition protocols. The radiomics model based on T1 imaging features alone resulted in a mean area under the curve (AUC) of 0·83, sensitivity of 0·68 and specificity of 0·84. Adding the T2‐weighted imaging features in an explorative analysis improved the model to a mean AUC of 0·89, sensitivity of 0·74 and specificity of 0·88. The three radiologists scored an AUC of 0·74 and 0·72 and 0·61 respectively; a sensitivity of 0·74, 0·91 and 0·64; and a specificity of 0·55, 0·36 and 0·59.

Conclusion

Radiomics is a promising, non‐invasive method for differentiating between WDLPS and lipoma, outperforming the scores of the radiologists. Further optimization and validation is needed before introduction into clinical practice.

Clarification of Decomposition Pathways in a State-of-the-Art Lithium Ion Battery Electrolyte through 13 C-Labeling of Electrolyte Components

The decomposition of state-of-the-art lithium ion battery (LIB) electrolytes leads to a highly complex mixture during battery cell operation. Furthermore, thermal strain by e.g., fast charging can initiate the degradation and generate various compounds. The correlation of electrolyte decomposition products and LIB performance fading over life-time is mainly unknown. The thermal and electrochemical degradation in electrolytes comprising 1 m LiPF6 dissolved in 13 C3 -labeled ethylene carbonate (EC) and unlabeled diethyl carbonate is investigated and the corresponding reaction pathways are postulated. Furthermore, a fragmentation mechanism assumption for oligomeric compounds is depicted. Soluble decomposition products classes are examined and evaluated with liquid chromatography-high resolution mass spectrometry. This study proposes a formation scheme for oligo phosphates as well as contradictory findings regarding phosphate-carbonates, disproving monoglycolate methyl/ethyl carbonate as the central reactive species.