Orbital state and magnetic properties of LiV_2 O_4

LiV_2 O_4 is one of the most puzzling compounds among transition metal oxides because of its heavy fermion like behavior at low temperatures. In this paper we present results for the orbital state and magnetic properties of LiV_2 O_4 obtained from a combination of density functional theory within the local density approximation and dynamical mean-field theory (DMFT). The DMFT equations are solved by quantum Monte Carlo simulations. The trigonal crystal field splits the V 3d orbitals such that the a_{1g} and e_{g}^{pi} orbitals cross the Fermi level, with the former being slightly lower in energy and narrower in bandwidth. In this situation, the d-d Coulomb interaction leads to an almost localization of one electron per V ion in the a_{1g} orbital, while the e_{g}^{pi} orbitals form relatively broad bands with 1/8 filling. 2The theoretical high-temperature paramagnetic susceptibility chi(T) follows a Curie-Weiss law with an effective paramagnetic moment p_{eff}=1.65 in agreement with the experimental results.Comment: 11 pages, 10 figures, 2 table

Pre-hospital management protocols and perceived difficulty in diagnosing acute heart failure

Aim To illustrate the pre-hospital management arsenals and protocols in different EMS units, and to estimate the perceived difficulty of diagnosing suspected acute heart failure (AHF) compared with other common pre-hospital conditions. Methods and results A multinational survey included 104 emergency medical service (EMS) regions from 18 countries. Diagnostic and therapeutic arsenals related to AHF management were reported for each type of EMS unit. The prevalence and contents of management protocols for common medical conditions treated pre-hospitally was collected. The perceived difficulty of diagnosing AHF and other medical conditions by emergency medical dispatchers and EMS personnel was interrogated. Ultrasound devices and point-of-care testing were available in advanced life support and helicopter EMS units in fewer than 25% of EMS regions. AHF protocols were present in 80.8% of regions. Protocols for ST-elevation myocardial infarction, chest pain, and dyspnoea were present in 95.2, 80.8, and 76.0% of EMS regions, respectively. Protocolized diagnostic actions for AHF management included 12-lead electrocardiogram (92.1% of regions), ultrasound examination (16.0%), and point-of-care testings for troponin and BNP (6.0 and 3.5%). Therapeutic actions included supplementary oxygen (93.2%), non-invasive ventilation (80.7%), intravenous furosemide, opiates, nitroglycerine (69.0, 68.6, and 57.0%), and intubation 71.5%. Diagnosing suspected AHF was considered easy to moderate by EMS personnel and moderate to difficult by emergency medical dispatchers (without significant differences between de novo and decompensated heart failure). In both settings, diagnosis of suspected AHF was considered easier than pulmonary embolism and more difficult than ST-elevation myocardial infarction, asthma, and stroke. Conclusions The prevalence of AHF protocols is rather high but the contents seem to vary. Difficulty of diagnosing suspected AHF seems to be moderate compared with other pre-hospital conditions

The nonperturbative functional renormalization group and its applications

The renormalization group plays an essential role in many areas of physics, both conceptually and as a practical tool to determine the long-distance low-energy properties of many systems on the one hand and on the other hand search for viable ultraviolet completions in fundamental physics. It provides us with a natural framework to study theoretical models where degrees of freedom are correlated over long distances and that may exhibit very distinct behavior on different energy scales. The nonperturbative functional renormalization-group (FRG) approach is a modern implementation of Wilson's RG, which allows one to set up nonperturbative approximation schemes that go beyond the standard perturbative RG approaches. The FRG is based on an exact functional flow equation of a coarse-grained effective action (or Gibbs free energy in the language of statistical mechanics). We review the main approximation schemes that are commonly used to solve this flow equation and discuss applications in equilibrium and out-of-equilibrium statistical physics, quantum many-particle systems, high-energy physics and quantum gravity.Comment: v2) Review article, 93 pages + bibliography, 35 figure

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Télémédecine et urgences : pertinence de la réponse d'un centre de réception et de régulation des appels

The principal objective of this study was to assess the adequacy of the response of an Emergency Medical Assistance (EMS) call reception and dispatch centre (CRDC) to telephone calls for medical emergencies. The study also aimed to evaluate the medico-economic consequences of call management by this type of call centre, as well as the impact of unusual public health events on the activities of the CRDC. With a view to this, prospective, comparative and observational clinical studies were conducted. The main results show that the recourse to telemedicine constitutes an appropriate response to emergency medical calls in terms of efficiency and satisfaction. With regard to benign but frequent indicator complaints, such as fever or gastroenteritis, or indeed severe pathologies which arise as part of rare medical conditions such as hereditary angio-oedema, distant telephone advice resulted in excellent patient compliance and was an appropriate response. Medico-economic analysis demonstrated a societal benefit from the medical telephone advice delivered by the CRDC. It was also shown that unusual public health situations could be detected through changes in the activity of a CRDC. Together these studies allow, for the first time, to objectively measure the appropriateness of medical call management. The results demonstrate a real benefit to patients, as well as a medicoeconomic efficiency in terms of healthcare use such as Emergency Department attendances or General Practice consultations. This study opens the path to future research into the efficiency of telemedicine.L’objectif de ce travail était d’évaluer la pertinence de la réponse d’un centre de réception et de régulation des appels (Crra) du service d’aide médicale urgente (SAMU) à des appels pour une urgence médicale. Notre étude a aussi cherché à évaluer les conséquences médico-économiques de la réponse de ce type de centre d’appels ainsi que l’impact d'événements exceptionnels sur l’activité de la régulation médicale. Dans ces buts, nous avons réalisé des études cliniques prospectives, comparatives et observationnelles. Nos principaux résultats ont permis de montrer que le recours à la télémédecine constituait une réponse pertinente en termes d’efficience et de satisfaction. Concernant des pathologies marqueuses bénignes mais fréquentes comme la fièvre ou la gastroentérite ou bien alors des pathologies graves au cours de maladies rares comme la crise d’angiœdème héréditaire, le conseil téléphonique à distance retrouvait une observance excellente et constituait une réponse adaptée. L’analyse médico-économique démontrait un bénéfice sociétal pour le conseil médical téléphonique pratiqué par un Crra. Nous avons montré que des événements sanitaires exceptionnels pouvaient être détectés par des variations d’activités du Crra. L’ensemble de ces recherches a permis, pour la première fois, d’objectiver la pertinence de la régulation médicale. Les résultats démontrent un réel service rendu pour le patient et un impact médico-économique synonyme d’économie en terme de consommation de ressources de santé comme l’hospitalisation aux urgences ou la consultation auprès des médecins généralistes. Notre étude ouvre la voie aux futures recherches sur l’efficience de la télémédecine

Telemedicine and emergencies : relevance of the response of a call reception and dispatch centre

L’objectif de ce travail était d’évaluer la pertinence de la réponse d’un centre de réception et de régulation des appels (Crra) du service d’aide médicale urgente (SAMU) à des appels pour une urgence médicale. Notre étude a aussi cherché à évaluer les conséquences médico-économiques de la réponse de ce type de centre d’appels ainsi que l’impact d'événements exceptionnels sur l’activité de la régulation médicale. Dans ces buts, nous avons réalisé des études cliniques prospectives, comparatives et observationnelles. Nos principaux résultats ont permis de montrer que le recours à la télémédecine constituait une réponse pertinente en termes d’efficience et de satisfaction. Concernant des pathologies marqueuses bénignes mais fréquentes comme la fièvre ou la gastroentérite ou bien alors des pathologies graves au cours de maladies rares comme la crise d’angiœdème héréditaire, le conseil téléphonique à distance retrouvait une observance excellente et constituait une réponse adaptée. L’analyse médico-économique démontrait un bénéfice sociétal pour le conseil médical téléphonique pratiqué par un Crra. Nous avons montré que des événements sanitaires exceptionnels pouvaient être détectés par des variations d’activités du Crra. L’ensemble de ces recherches a permis, pour la première fois, d’objectiver la pertinence de la régulation médicale. Les résultats démontrent un réel service rendu pour le patient et un impact médico-économique synonyme d’économie en terme de consommation de ressources de santé comme l’hospitalisation aux urgences ou la consultation auprès des médecins généralistes. Notre étude ouvre la voie aux futures recherches sur l’efficience de la télémédecine.The principal objective of this study was to assess the adequacy of the response of an Emergency Medical Assistance (EMS) call reception and dispatch centre (CRDC) to telephone calls for medical emergencies. The study also aimed to evaluate the medico-economic consequences of call management by this type of call centre, as well as the impact of unusual public health events on the activities of the CRDC. With a view to this, prospective, comparative and observational clinical studies were conducted. The main results show that the recourse to telemedicine constitutes an appropriate response to emergency medical calls in terms of efficiency and satisfaction. With regard to benign but frequent indicator complaints, such as fever or gastroenteritis, or indeed severe pathologies which arise as part of rare medical conditions such as hereditary angio-oedema, distant telephone advice resulted in excellent patient compliance and was an appropriate response. Medico-economic analysis demonstrated a societal benefit from the medical telephone advice delivered by the CRDC. It was also shown that unusual public health situations could be detected through changes in the activity of a CRDC. Together these studies allow, for the first time, to objectively measure the appropriateness of medical call management. The results demonstrate a real benefit to patients, as well as a medicoeconomic efficiency in terms of healthcare use such as Emergency Department attendances or General Practice consultations. This study opens the path to future research into the efficiency of telemedicine

Numerical and Experimental Investigations of Coupling Effects in Anisotropic Elastic Rotors

It is known that in elastic disc-shaft systems in particular, the one-nodal-diameter mode of the discs can be highly coupled with the bending modes of the shaft. Consequently, when the system rotates, the elastic modes of the flexible discs are coupled with the gyroscopic modes of the flexible shaft equipped with rigid discs. In the paper this coupling effect is investigated numerically and experimentally

Optimisation of the corrosion rate of iron-based alloys for bioresorbable stent applications by surface acidification

Biodegradable materials become progressively of interest for stent applications. However, during the corrosion of a stent in the blood environment, different layers form on top of the metal, hindering the oxygen diffusion towards the metal. Since the pH of the environment greatly influences the presence of these layers, dissolution of these layers could help in activating the corrosion. The present work thus investigates different methods that can influence the pH: dissolved hydrogen and polymer coating on Fe-based alloys. Hydrogen charging was conducted either electrochemically, thermally or chemically on Fe-Mn-C TWIP steels also containing VC precipitates for hydrogen pinning. The effect of these carbides on the mechanical behaviour with different levels of hydrogen was studied. The influence of the hydrogen concentration on the corrosion mechanisms in SBF (simulated body fluid) is assessed by means of immersion tests as well as potentiodynamic polarisation tests. Immersion tests allow to mimic closely what happens in vivo, while potentiodynamic polarisation tests give a quick comparison between the different materials regarding their corrosion rates. Samples charged electrochemically showed an increased corrosion rate for samples that contained higher amounts of hydrogen (after one day of immersion). On the other hand, after three days of immersion, no significant effect could be seen. This can be explained by the fact that no hydrogen is present in the sample anymore after 3 days at room temperature (assessed by Thermal Desorption Analysis). For the polymer method, a PLA (polylactic acid) coating was performed on the Fe-Mn-C surface. It can be seen that the corrosion rate is increased after addition of this coating. This can be explained by the hydrolysis of the polymer, which acidifies the surface and dissolves the corrosion products