Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion

Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency.

CISMeF: A Structured Health Resource Guide

In 1999, the Internet has become a major source of health information. The objective of CISMeF is to catalogue and index the main French-speaking health resources. In September 1999, the number of indexed resources totaled over 7,100 with a mean of 75 new sites per week. CISMeF uses two standard tools for organizing information: the Medline bibliographic database MeSH thesaurus and the Dublin Core metadata format. Resources included in CISMeF are described by the following: title, author or creator, subject and keywords, description, publisher, date, resource type, format, identifier, and language. To index resources, CISMeF uses five levels of hierarchy: “meta-term”, category, keyword, subheading, and resource type. CISMeF contains a thematic index, including medical specialities and an alphabetic index. CISMeF respects the Net Scoring, criteria to assess the quality of health information on the Internet. The CISMeF project offers a valuable tool for the French-speaking health community: 2,500 computer users visit the Web site each working day.

An elevated respiratory quotient predicts complications after cardiac surgery under extracorporeal circulation: an observational pilot study

Following cardiac surgery, hyperlactatemia due to anaerobic metabolism is associated with an increase in both morbidity and mortality. We previously found that an elevated respiratory quotient (RQ) predicts anaerobic metabolism. In the present study we aimed to demonstrate that it is also associated with poor outcome following cardiac surgery. This single institution, prospective, observational study includes all those patients that were consecutively admitted to the intensive care unit (ICU) after cardiac surgery with cardiopulmonary bypass, that had also been monitored using pulmonary artery catheter. Data were recorded at admission (H0) and after one hour (H1) including: oxygen consumption ([Formula: see text]), carbon dioxide production ([Formula: see text]), RQ ([Formula: see text]), lactate levels and mixed venous oxygen saturation ([Formula: see text]). The primary endpoint was defined as mortality at 30 days. Comparison of the area under the curve (AUC) for receiver operating characteristic curves was used to analyze the prognostic predictive value of RQ, lactate levels and [Formula: see text], in terms of patient outcome. We studied 151 patients admitted to the ICU between May 2015 and February 2016. Seventy eight patients experienced a worse than expected outcome in the post-operative period, and among those seven died. RQ at H1 in non-survivors ([Formula: see text]) was higher than in survivors ([Formula: see text]; p = 0.02). The AUC for RQ to predict mortality was 0.77 (IC95% [0.70-0.84]), with a threshold value of 0.76 (sensitivity 64%, specificity 100%). By comparison, the AUC for lactate levels was significantly superior (AUClact 0.89, IC95% [0.83-0.93], p = 0.02). In this study, elevated RQ appeared to be predictive of mortality after cardiac surgery with CPB.

Shell-structure and pairing interaction in superheavy nuclei: rotational properties of the z=104 nucleus (256)rf

The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin of 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents the first such measurement in a superheavy nucleus whose stability is entirely derived from the shell-correction energy. The observed rotational properties are compared to those of neighboring nuclei and it is shown that the kinematic and dynamic moments of inertia are sensitive to the underlying single-particle shell structure and the specific location of high-j orbitals. The moments of inertia therefore provide a sensitive test of shell structure and pairing in superheavy nuclei which is essential to ensure the validity of contemporary nuclear models in this mass region. The data obtained show that there is no deformed shell gap at Z=104, which is predicted in a number of current self-consistent mean-field models.

4D-imaging of drip-line radioactivity by detecting proton emission from 54mNi pictured with ACTAR TPC

Proton radioactivity was discovered exactly 50 years ago. First, this nuclear decay mode sets the limit of existence on the nuclear landscape on the neutron-deficient side. Second, it comprises fundamental aspects of both quantum tunnelling as well as the coupling of (quasi)bound quantum states with the continuum in mesoscopic systems such as the atomic nucleus. Theoretical approaches can start either from bound-state nuclear shell-model theory or from resonance scattering. Thus, proton-radioactivity guides merging these types of theoretical approaches, which is of broader relevance for any few-body quantum system. Here, we report experimental measurements of proton-emission branches from an isomeric state in ^54mNi, which were visualized in four dimensions in a newly developed detector. We show that these decays, which carry an unusually high angular momentum, ℓ = 5 and ℓ = 7, respectively, can be approximated theoretically with a potential model for the proton barrier penetration and a shell-model calculation for the overlap of the initial and final wave functions.

Proton radioactivity is useful for studying nuclear structure. Here the authors report two proton emission branches from the 10+ state isomer of 54mNi by using a time projection chamber.

Fission barrier of superheavy nuclei and persistence of shell effects at high spin: cases of 254No and 220Th

We report on the first measurement of the fission barrier height in a heavy shell-stabilized nucleus. The fission barrier height of 254No is measured to be Bf=6.0±0.5  MeV at spin 15ℏ and, by extrapolation, Bf=6.6±0.9  MeV at spin 0ℏ. This information is deduced from the measured distribution of entry points in the excitation energy versus spin plane. The same measurement is performed for 220Th and only a lower limit of the fission barrier height can be determined: Bf(I)>8  MeV. Comparisons with theoretical fission barriers test theories that predict properties of superheavy elements.

First Direct Measurement of Isotopic Fission-Fragment Yields of ^{239}U

A direct and complete measurement of isotopic fission-fragment yields of ^{239}U has been performed for the first time. The ^{239}U fissioning system was produced with an average excitation energy of 8.3 MeV in one-neutron transfer reactions between a ^{238}U beam and a ^{9}Be target at Coulomb barrier energies. The fission fragments were detected and isotopically identified using the VAMOS++ spectrometer at the GANIL facility. The measurement allows us to directly evaluate the fission models at excitation energies of fast neutrons, which are relevant for next-generation nuclear reactors. The present data, in agreement with model calculations, do not support the recently reported anomaly in the fission-fragment yields of ^{239}U, and they confirm the persistence of spherical shell effects in the Sn region at excitation energies exceeding the fission barrier by a few mega-electron volts.

Assessment of neutron dosemeters around standard sources and nuclear fissile objects

In order to evaluate the neutron doses around nuclear fissile objects, a comparative study has been made on several neutron dosemeters: bubble dosemeters, etched-track detectors (CR-39) and 3He-filled proportional counters used as dose-rate meters. The measurements were made on the ambient and the personal dose equivalents H*(10) and Hp(10). Results showed that several bubble dosemeters should have been used due to a low reproducibility in the measurements. A strong correlation with the neutron energy was also found, with about a 30% underestimation of Hp(10) for neutrons from the PuBe source, and about a 9% overestimation for neutrons from the 252Cf source. Measurements of the nuclear fissile objects were made using the CR-39 and the dose-rate meters. The CR-39 led to an underestimation of 30% with respect to the neutron dose-rate meter measurements. In addition, the MCNP calculation code was used in the different configurations.

Gamma-ray spectroscopy at the limits: first observation of rotational bands in 255Lr

The rotational band structure of 255Lr has been investigated using advanced in-beam gamma-ray spectroscopic techniques. To date, 255Lr is the heaviest nucleus to be studied in this manner. One rotational band has been unambiguously observed and strong evidence for a second rotational structure was found. The structures are tentatively assigned to be based on the 1/2-[521] and 7/2-[514] Nilsson states, consistent with assignments from recently obtained alpha decay data. The experimental rotational band dynamic moment of inertia is used to test self-consistent mean-field calculations using the Skyrme SLy4 interaction and a density-dependent pairing force.

Early extubation in extracorporeal life support patients: A propensity score-matched study

BACKGROUND

Extubation strategy in extracorporeal life support patients remains unclear, and literature only reports studies with significant biases.

OBJECTIVES

To explore the prognostic impact of an early ventilator-weaning strategy in assisted patients after controlling for confounding factors.

METHODS

A 10-year retrospective study included 241 patients receiving extracorporeal life support for at least 48 h, corresponding to a total of 977 days spent on assistance. The a priori probability of extubation for each day of assistance was calculated according to daily biological examinations, drug doses, clinical observations, and admission data to pair each day containing an extubation with one on which the patient was not extubated. The primary outcome was survival at day 28. The secondary outcomes were survival at day 7, respiratory infections, and safety criteria.

RESULTS

Two similar cohorts of 61 patients were generated. Survival at day 28 was better in patients extubated under assistance in univariate and multivariate (HR = 0.37 [0.2-0.68], p-value = 0.002) analyses. Patients who underwent failed early extubation did not have a different prognosis from those without early extubation. Successful early extubation was associated with a better outcome than a failed or no attempt at early extubation. Survival at day 7 and the rate of respiratory infections were better in early-extubated patients. Safety data did not differ between the two groups.

CONCLUSIONS

Early extubation during assistance was associated with a superior outcome in our propensity-matched cohort study. The safety data were reassuring. However, due to the lack of prospective randomized studies, the causality remains uncertain.

Study of High-Energy Fission in Inverse Kinematics

Fission at low excitation energy, is a process in which both macroscopic and microscopic aspects are involved. Some features in the total kinetic energy and in the N/Z distributions of the fragments, commonly associated with shell effects, came out in a series of recent experiments with high excitation energy fusionfission reactions in inverse kinematics. In the latest experiment of this campaign, a study of high-energy fission and quasi-fission between a 238U beam and a series of light targets was carried out by using the aforementioned technique, in order to probe the role of the shell structure in these processes.

CISMeF: a structured health resource guide

In 1999, the Internet has become a major source of health information. The objective of CISMeF is to catalogue and index the main French-speaking health resources. In September 1999, the number of indexed resources totaled over 7,100 with a mean of 75 new sites per week. CISMeF uses two standard tools for organizing information: the Medline bibliographic database MeSH thesaurus and the Dublin Core metadata format. Resources included in CISMeF are described by the following: title, author or creator, subject and keywords, description, publisher, date, resource type, format, identifier, and language. To index resources, CISMeF uses five levels of hierarchy: "meta-term", category, keyword, subheading, and resource type. CISMeF contains a thematic index, including medical specialities and an alphabetic index. CISMeF respects the Net Scoring, criteria to assess the quality of health information on the Internet. The CISMeF project offers a valuable tool for the French-speaking health community: 2,500 computer users visit the Web site each working day.

Doc'CISMEF: a search tool based on "encapsulated" MeSH thesaurus

In the year 2000, the Internet became a major source of health information for the health professional and the Netizen. The objective of Doc'CISMeF (D'C) was to create a powerful generic search tool based on an structured information model which â encapsulates' the MeSH thesaurus to index and retrieve quality health resources on the Internet. To index resources, D'C uses four sections in its information model: 'meta-term', keyword, subheading, and resource type. Two search options are available: simple and advanced. The simple search requires the end-user to input a single term or expression. If this term belongs to the D'C information structure model, it will be exploded. If not, a full-text search is performed. In the advanced search, complex searches are possible combining Boolean operators with meta-terms, keywords, subheadings and resource types. D'C uses two standard tools for organising information: the MeSH thesaurus and the Dublin Core metadata format. Resources included in D'C are described according to the following elements: title, author or creator, subject and keywords, description, publisher, date, resource type, format, identifier, and language.

French Infobutton: an academic and business perspective

Infobuttons are context-specific links between clinical information systems and other online information resources. The objective of this study is to describe a French Infobutton, which will be sold in the French-speaking Health Information market.

Preoperative fibrinogen level and postcardiac surgery morbidity and mortality rates

BACKGROUND

High preoperative fibrinogen levels are associated with reduced bleeding rates after cardiac surgery. Fibrinogen is directly involved in inflammatory processes and is a cardiovascular risk factors. Whether high fibrinogen levels before cardiac surgery are a risk factor for mortality or morbidity remains unclear.

AIMS

This study aimed to examine the association between preoperative fibrinogen levels and mortality and morbidity rates after cardiac surgery.

SETTINGS AND DESIGN

This is a single-center retrospective study.

MATERIAL AND METHODS

Patients (n = 1628) were divided into high (HFGr) and normal (NFGr) fibrinogen level groups, based on the cutoff value of 3.3 g/L, derived from the receiver operating characteristic (ROC) curve analysis. The primary outcome was the 30-day mortality rate. The rates of postoperative complications, including postoperative bleeding and transfusion rates, were examined.

STATISTICAL ANALYSIS

Between-group comparisons were performed with the Mann-Whitney U test and Chi-squared test, as suitable. Model discriminative power was examined with the area under the ROC curve.

RESULTS

The HFGr and NFGr included 1103 and 525 patients, respectively. Mortality rate was higher in the HFGr than in the NFGr (2.7% vs. 1.1%, P = 0.04). The 12-h bleeding volume (280 mL [195-400] vs. 305 mL [225-435], P = 0.0003) and 24-h bleeding volume values (400 mL [300-550] vs. 450 mL [340-620], P < 0.0001) were lower in the HFGr than in the NFGr. However, the rate of red blood cell transfusion during hospitalization was higher in the HFGr than in the NFGr (21.7% vs. 5.9%, P = 0.0103). Major complications were more frequent in the HFGr than in the NFGr.

CONCLUSION

High fibrinogen levels were associated with reduced postoperative bleeding volume and increased mortality and morbidity rates.

CISMeF: cataloque and index of French speaking health resources

In 1999, the Internet has become a major source of health information. The objective of CISMeF is to catalogue and index the main French-speaking sites and documents concerning health. Currently, the number of resources already totalled over 6,100 with a mean of 75 new sites each week. CISMeF contains a thematic index, including medical specialities and an alphabetic index. CISMeF uses two standard tools for organising information: the MeSH (Medical Subject Heading) thesaurus from the Medline bibliographic database (National Library of Medicine) and the Dublin Core metadata format. A brief description of the site is systematically added. CISMeF respects the Net Scoring, criteria to assess the quality of health information on the Internet. The CISMeF project fulfils a valuable tool for the French-speaking health community: 2,500 machines visit the Web site each working day.

Quality of life of patients with solid malignancies at 3 months after unplanned admission in the intensive care unit: A prospective case-control study

BACKGROUND

Although short- and long-term survival in critically ill patients with cancer has been described, data on their quality of life (QoL) after an intensive care unit (ICU) stay are scarce. This study aimed to determine the impact of an ICU stay on QoL assessed at 3 months in patients with solid malignancies.

METHODS

A prospective case-control study was conducted in three French ICUs between February 2020 and February 2021. Adult patients with lung, colorectal, or head and neck cancer who were admitted in the ICU were matched in a 1:2 ratio with patients who were not admitted in the ICU regarding their type of cancer, curative or palliative anticancer treatment, and treatment line. The primary endpoint was the QoL assessed at 3 months from inclusion using the mental and physical components of the Short Form 36 (SF-36) Health Survey. The use of anticancer therapies at 3 months was also evaluated.

RESULTS

In total, 23 surviving ICU cancer patients were matched with 46 non-ICU cancer patients. Four patients in the ICU group did not respond to the questionnaire. The mental component score of the SF-36 was higher in ICU patients than in non-ICU patients: median of 54 (interquartile range: 42-57) vs. 47 (37-52), respectively (p = 0.01). The physical component score of the SF-36 did not differ between groups: 35 (31-47) vs. 42 (34-47) (p = 0.24). In multivariate analysis, no association was found between patient QoL and an ICU stay. A good performance status and a non-metastatic cancer at baseline were independently associated with a higher physical component score. The use of anticancer therapies at 3 months was comparable between the two groups.

CONCLUSION

In patients with solid malignancies, an ICU stay had no negative impact on QoL at 3 months after discharge when compared with matched non-ICU patients.

[CISMeF: catalog and index of French-speaking medical sites]

The Internet has now become a major source of health information. The aim of CISMeF is to catalogue and index the main French-speaking sites and documents concerning health. This project was initiated by Rouen University Hospital. Its URL is http://www.chu-rouen.fr/cismef. CISMeF covers all areas of health care and medical sciences, and is indexed both alphabetically and according to subject. It was set up on a Sun workstation under the Sun UNIX operating system and is entirely based on static HTML. By May 1999, the number of sites and documents indexed was already over 6,500, with a mean of 75 new sites added each week. CISMeF is updated via a five-step process: resource collection, filtering, description, classification, and indexing. The Net Scoring criteria are used to assess the quality of health information on the Internet. These criteria concern eight categories: credibility, content, links, design, interactivity, quantitative aspects, ethics and accessibility. CISMeF uses two standard tools to organize information: the MeSH (medical subject heading) thesaurus from the Medline reference database (National Library of Medicine, USA) and the Dublin core metadata format. The sites and documents included in CISMeF are described using the following elements from the Dublin core project: title, author or creator, subject and keywords, description, publisher, date, resource type, format, identifier, and language.

Search for a Neutron Dark Decay in ^{6}He

Neutron dark decays have been suggested as a solution to the discrepancy between bottle and beam experiments, providing a dark matter candidate that can be searched for in halo nuclei. The free neutron in the final state following the decay of ^{6}He into ^{4}He+n+χ provides an exceptionally clean detection signature when combined with a high efficiency neutron detector. Using a high-intensity ^{6}He^{+} beam at Grand Accélérateur National d'Ions Lourds, a search for a coincident neutron signal resulted in an upper limit on a dark decay branching ratio of Br_{χ}≤4.0×10^{-10} (95% C.L.). Using the dark neutron decay model proposed originally by Fornal and Grinstein, we translate this into an upper bound on a dark neutron branching ratio of O(10^{-5}), improving over global constraints by one to several orders of magnitude depending on m_{χ}.