Supercritical Water: A Simulation Study to Unravel the Heterogeneity of Its Molecular Structures.

(1) Background: In the quest to accurately model the radiolysis of water in its supercritical state, a detailed understanding of water's molecular structure, particularly how water molecules are arranged in this unique state, is essential. (2) Methods: We conducted molecular dynamics simulations using the SPC/E water model to investigate the molecular structures of supercritical water (SCW) over a wide temperature range, extending up to 800 °C. (3) Results: Our results show that at a constant pressure of 25 MPa, the average intermolecular distance around a reference water molecule remains remarkably stable at ~2.9 Å. This uniformity persists across a substantial temperature range, demonstrating the unique heterogeneous nature of SCW under these extreme conditions. Notably, the simulations also reveal intricate patterns within SCW, indicating the simultaneous presence of regions with high and low density. As temperatures increase, we observe a rise in the formation of molecular clusters, which are accompanied by a reduction in their average size. (4) Conclusions: These findings highlight the necessity of incorporating the molecular complexity of SCW into traditional track-structure chemistry models to improve predictions of SCW behavior under ionizing radiation. The study establishes a foundational reference for further exploration of the properties of supercritical water, particularly for its application in advanced nuclear technologies, including the next generation of water-cooled reactors and their small modular reactor variants that utilize SCW as a coolant.

[GENDER AND PSYCHO-TRAUMA IN A CLOTHED BODY: A CASE OF ONIRISM IN THE AFTERLIFE]. / Genre et psycho traumatisme chez un corps habillé : cas d'onirisme dans l'au-delà.

Introduction: Ce fait clinique met en relief la profondeur d'une atteinte psychique en recomposition avec la vulnérabilité du genre, l'isolement professionnel, la religion et la culture où l'espace et le temps perdent totalement leur valeur. Observation: Occupant un poste de surveillance des chemins des braconniers très élongés avec une communication défaillante par moment, une jeune femme nourrice forestière à plusieurs fois fait des observations sur la dangerosité et l'absence de défense en cas d'attaque de ces positions professionnelles. Un petit matin, elle est retrouvée par hasard par un chasseur totalement baignant dans son sang avec des multiples coupures de coupe-coupe. Elle se réveille après 25 jours de coma et plus de trois séances de kinésithérapie sans aucune communication verbale. Arrivé en entretien chez le psychiatre, elle a un regard hagard avec une torpeur. Elle finit à la deuxième séance par s'interroger de la raison de la présence dans ce lieu au premier contact avec son enfant qu'elle considère au paradis. Seul l'instinct maternel, l'a fait sortie de son état quasi indescriptible après le trauma psychique. Conclusion: Il est impératif aux professionnels de la santé des corps utilisateurs des armes à feu d'être attentif à la souffrance psychique en relation avec le genre et les conditions culturelles. Mots clés: Psycho-traumatisme, Genre, Insécurité, Afrique subsaharienne.

[SUICIDAL IDEATIONS AMONG STUDENTS IN THE FACULTY OF HEALTH SCIENCES AT PUBLIC UNIVERSITIES IN TOGO]. / Idéations suicidaires chez les étudiants en faculté des sciences de la santé des universités publiques du Togo.

Introduction: Le but de ce travail était de déterminer la prévalence des idéations suicidaires et leurs facteurs associés chez les étudiants en faculté des sciences de la santé au Togo. Méthodes: Il s'est agi d'une étude transversale auprès des étudiants de médecine, pharmacie et odontostomatologie des universités publiques du Togo, du 1er juillet au 30 septembre 2021. Les données ont été recueillies à partir d'un questionnaire individuel en formulaire GoogleForm dont le lien a été partagé à travers des groupes WhatsApp préexistants. Les données ont été traitées par le logiciel EPI INFO version 7.2.5.0. Les facteurs associés ont été étudiés en analyse univariée et multivariée. Résultats: Au total 587 étudiants de médecine, pharmacie et odonto-stomatologie ont été enquêté. La plupart des étudiants étaient de sexe masculin (62,86%) et en première année en sciences médicales. La prévalence des idéations suicidaires était de 26,24%. Les facteurs associés aux idéations suicidaires étaient le sexe féminin, un résultat universitaire non satisfaisant, une mauvaise qualité des relations parentales, un manque d'activités sportives, le niveau de 1er cycle d'études médicales, la consommation d'alcool, la consommation de substances psychoanaleptique et psycholeptiques, et un antécédant de dépression. Les idéations suicidaires étaient indépendamment associées à la consommation d'alcool, de substances psycholeptiques et un antécédent de dépression. Conclusion: le quart des étudiants en faculté des sciences de la santé au Togo avaient des idéations suicidaires.

[Sociodemographic and clinical characteristics of the populations admitted in the emergency service of the Campus University Hospital (Lome)]. / Caracteristiques sociodemographiques et cliniques des populations prise en charge aux urgences du chu campus (Lome).

AIMS: The objectives were to determine the prevalence of psychiatric emergencies and establish the sociodemographic and clinical characteristics of these patients. METHODOLOGY: Our work was set in the Clinic of Psychiatry and Medical Psychology and Medical Emergency Service of the University Hospital S. Olympio. It was a prospective study including a descriptive and analytical focus involving patients admitted from January 1 to December 31, 2013. RESULTS: The frequency was 5,52% of the patients. The average age of the patients was of 36.12±12.3 years with ranging from 14 to 87 years old. The sex-ratio was 0,45. Married or cohabitating patients were the most represented with 50.91%. The informal lower sector was the most affected (46.18%). The length of consultation was of 8.47±16.6 days. Acute and passing psychotic disorders, the reaction to severe adaptation stress and dissociative behaviors were respectively diagnosed for 39.64%, 33.45% and 6.55% of patients. CONCLUSION: Despite its low frequency, the knowledge of the profile of the users of the emergency service for mental disorders and their relative difficulties were necessary for the organization of good care management.

BUTS: Les objectifs étaient de déterminer la fréquence des urgences psychiatriques et d'identifier les caractéristiques sociodémogra-phiques et cliniques de ces patients. MÉTHODOLOGIE: Notre travail a eu pour cadre la Clinique de Psychiatrie et de Psychologie Médicale et le Service des Urgences Médicales du CHU Campus. Il s'est agi d'une étude prospective à visée descriptive et analytique incluant les patients reçu du 1er janvier au 31 décembre 2013. RÉSULTATS: La fréquence a été de 5,52% des patients. L'âge moyen des patients était de 36,12±12,3 ans avec des extrêmes allant de 14 à 87 ans. Le sex-ratio était de 0,45. Les patients mariés ou en concubinage étaient les plus représentés avec 50,91%. Le secteur informel de bas niveau était le plus atteint à 46,18 %. Le délai de consultation était de 8,47±16,6 jours. Les troubles psychotiques aigus et transitoires, La réaction à un stress sévère et trouble de l'adaptation et les troubles dissociatifs ont été diagnostiqués respectivement pour 39,64%, 33,45% et 6,55% de patients. CONCLUSION: Malgré sa faible fréquence, la connaissance du profil des usagers des urgences pour les troubles mentaux était nécessaire pour l'organisation d'une prise en charge adéquate.

[Care mechanisms and therapeutic aspects of the management of psychiatric emergencies in the Campus University Hospital (Lome)]. / Dispositif de soins et aspects therapeutiques de prise en charge des urgences psychiatriques au chu campus (lome).

INTRODUCTION: the objectives were to describe the mechanisms of psychiatric emergency care in a context of limited human resources and the existing therapeutic modalities within the general evaluation framework of the activity of the emergency service. METHODOLOGY: Our study was set in the Clinic of Psychiatry and Medical Psychology (CPMP) and the Emergency Medical Service (EMS) of the Campus University Hospital (Lome). It was a prospective study including a descriptive and analytical focus involving patients admitted from January 1 to December 31, 2013. RESULTS: the psychiatric emergencies during working hours were taken care of by the CPMP, out of our care and during holidays by the EMS. We identified 4977 admitted patients of which 275 cases for psychiatric emergencies, that is a frequency of 5.52% of the cases. The greatest activity was recorded in the afternoon (49.09%). The entourage of the patients (58.18%) was the highest applicant for urgent care. The majority of hospitalized patients (57.14%) were admitted under constraint and physical constraint during care was imposed for 14.55% of cases. Acute and transient psychotic disorders (39.64%), reaction to severe stress and adjustment disorder (33.45%) were predominant diagnoses. CONCLUSION: the specific difficulties in psychiatric emergency require the establishment of a legal framework and a better organization.

INTRODUCTION: Les objectifs étaient de décrire le dispositif de soins d'urgence psychiatrique dans un contexte de ressources humaines limités et les modalités thérapeutiques existantes dans le cadre d'évaluation générale de l'activité des urgences. MÉTHODOLOGIE: le cadre de notre travail a été la Clinique de Psychiatrie et de Psychologie Médicale (CPPM) et le Service des Urgences Médicales (SUM) du CHU Campus. Il s'est agi d'une étude prospective à visée descriptive et analytique incluant les patients reçus du 1er janvier au 31 décembre 2013. RÉSULTATS: Les urgences de psychiatrie aux heures ouvrables étaient assurées par la CPPM, la garde et jour fériés par le SUM de la porte. Nous avons recensé 4977 patients admis dont 275 cas pour les urgences psychiatriques, soit une fréquence globale de 5,52% des cas. La plus grosse activité avait été enregistrée dans l'après midi (49,09%). L'entourage des patients (58,18%) était le plus demandeur d'une prise en charge urgente. La plus part de nos patients hospitalisés (57,14%) ont été admis sous la contrainte et la contrainte physique aux soins était imposée pour 14,55% de cas. Les troubles psychotiques aigus et transitoires (39,64%) et la réaction à un stress sévère et trouble de l'adaptation (33,45%) ont été les diagnostics prédominants. CONCLUSION: les difficultés spécifiques à l'urgence psychiatriques nécessitent la mise en place d'un cadre légal et une meilleure organisation.

A decisional account of subjective inflation of visual perception at the periphery.

Human peripheral vision appears vivid compared to foveal vision; the subjectively perceived level of detail does not seem to drop abruptly with eccentricity. This compelling impression contrasts with the fact that spatial resolution is substantially lower at the periphery. A similar phenomenon occurs in visual attention, in which subjects usually overestimate their perceptual capacity in the unattended periphery. We have previously shown that at identical eccentricity, low spatial attention is associated with liberal detection biases, which we argue may reflect inflated subjective perceptual qualities. Our computational model suggests that this subjective inflation occurs because under the lack of attention, the trial-by-trial variability of the internal neural response is increased, resulting in more frequent surpassing of a detection criterion. In the current work, we hypothesized that the same mechanism may be at work in peripheral vision. We investigated this possibility in psychophysical experiments in which participants performed a simultaneous detection task at the center and at the periphery. Confirming our hypothesis, we found that participants adopted a conservative criterion at the center and liberal criterion at the periphery. Furthermore, an extension of our model predicts that detection bias will be similar at the center and at the periphery if the periphery stimuli are magnified. A second experiment successfully confirmed this prediction. These results suggest that, although other factors contribute to subjective inflation of visual perception in the periphery, such as top-down filling-in of information, the decision mechanism may be relevant too.

Effects of dietary cadmium contamination on bird Anas platyrhynchos--comparison with species Cairina moschata.

This study aimed to assess the effect of two dietary cadmium (Cd) levels (C1: 1 mgkg(-1); C10: 10 mgkg(-1)) on bird Anas platyrhynchos exposed for 10, 20 and 40 days (5 animals per experimental condition). Ducks were able to accumulate high amounts of Cd, especially in kidneys (after 40 days: C1 8.1 ± 1 mgkg(-1), C10 37.7 ± 4.3 mgkg(-1)). After 40 days, the lowest Cd level triggered oxidative stress and stimulated mitochondrial metabolism. At the same time, highest amounts of Cd (C10 group) only triggered repression of genes encoding for catalase and acetyl-CoA carboxylase, with repression factors of 1/50 and 1/5, respectively. High dose exposures were then associated with the repression of genes encoding for antioxidant, whereas low dose exposure triggered their induction. In contrast, the onset of MT gene expression appeared quickly for the C10 group even if a time delay was observed between gene expression and protein accumulation. Through the comparison of A. platyrhynchos and Cairina moschata, the response to Cd toxicity appeared species-dependent. Discrepancies between species could be explained by differential utilization of MT. This pathway of detoxification seemed sufficient to counter Cd toxicity.

Effect of dietary cadmium on lipid metabolism and storage of aquatic bird Cairina moschata.

In environment, birds often fast in connection with breeding, migration or drastic climatic conditions and need to mobilize lipid reserves during these periods. The impairment of lipid metabolism by cadmium (Cd; 1 mg kg(-1) added in diet) was investigated on palmiped Cairina moschata. Expression levels of genes involved in lipid metabolism, mitochondrial metabolism and detoxification were investigated in liver and muscle of ducks. Lipid content in muscle and liver were analysed and plasma triglycerides were quantified. After 20 days, ducks exposed to Cd displayed a lower body weight and lower lipid content in liver than controls. In muscle, the increase of lipid content was only significant for control ducks but not for exposed ducks. Exposed ducks appeared unable to sufficiently transport and store lipids into peripheral tissues. Cd impairs lipid metabolism by several ways. First, Cd triggered the down-regulation of fatty acids synthesis in liver even if the NADPH production and the mitochondrial metabolism are enhanced, suggesting a stronger energy needs. Secondly, the associated decrease of plasma triglycerides and lipoprotein lipase activity with Cd are consistent with impairment of lipids storage in peripheral tissues.

Does overfeeding enhance genotype effects on energy metabolism and lipid deposition in breast muscle of ducks?

We evaluated the effects of genotype (Muscovy, Pekin and their crossbreed hinny and mule ducks) and feeding levels (overfeeding between 12 and 14 weeks of age vs ad libitum feeding) on energy metabolism and lipid deposition in breast muscle of ducks. Samples of breast muscle (Pectoralis major) were collected at 14 weeks of age from 8 birds per group. Overfeeding induced an accumulation of lipids in breast muscle (1.5- to 1.7-fold, depending on genotype) mainly induced by triglyceride deposition. It also induced a considerable increase in the amounts (expressed as g/100 g of tissue) of saturated and mono-unsaturated fatty acids (SFA, MUFA), while the amounts of poly-unsaturated fatty acids (PUFA) remained unchanged in hinny and Muscovy ducks or slightly increased in Pekin and mule ducks. In breast muscle, overfeeding decreased the activity of the main enzymes involved in lipogenesis from glucose (glucose-6-phosphate dehydrogenase, G6PDH, malic enzyme, ME, acetyl CoA carboxylase, ACX). Lipoprotein lipase (LPL) activity in Pectoralis major muscle was also significantly decreased (-21%). The ability of muscle tissues to catabolize long-chain fatty acids, as assessed by beta-hydroxyacyl CoA dehydrogenase (HAD) activity, was increased in Pectoralis major muscle, as was cytochrome-c oxidase (COX) activity. Hybrid and Pekin ducks exhibited higher levels of ACX and LPL activity in Pectoralis major muscle than Muscovy ducks, suggesting a greater ability to synthesise lipids in situ, and to take up circulating lipids. Total lipid content in breast muscle of hybrid and Pekin ducks was higher than in that of Muscovy ducks. In hybrid and Pekin ducks, lipid composition of breast muscle was characterized by higher amounts of triglycerides, SFA and MUFA than in Muscovy ducks. Finally, oxidative metabolism was greater in Pectoralis major muscles of hybrid and Pekin ducks than in Muscovy ducks, suggesting an adaptative strategy of muscle energy metabolism according to lipid level.

Does overfeeding enhance genotype effects on liver ability for lipogenesis and lipid secretion in ducks?

We evaluated the effects of genotype (Muscovy, Pekin and their crossbreed hinny and mule ducks) and feeding levels (overfeeding between 12 and 14 weeks of age vs ad libitum feeding) on liver ability for lipogenesis and lipid secretion in ducks. Samples of liver and blood were collected at 14 weeks of age from 8 birds per group. Plasma levels of insulin was considerably increased in overfed ducks (1.9-fold), stimulating the hepatic activity of the main enzymes involved in lipogenesis from glucose (glucokinase, GK, glucose-6-phosphate dehydrogenase, G6PDH, malic enzyme, ME, acetyl CoA carboxylase, ACX), while cytochrome-c oxidase (COX) activity, indicating overall oxidation ability of energy-yielding substrates, remained unchanged. Plasma levels of triglycerides, phospholipids and total cholesterol were therefore increased (1.9, 3.7, 1.6 and 1.6-fold, respectively). Glycaemia also significantly increased (+8%). Pekin ducks exhibited higher levels of GK and G6PDH activity in the liver than Muscovy ducks, suggesting a greater ability to use glucose consistent with their lower glycaemia. Muscovy ducks had greater ACX activity, suggesting greater ability to synthesise lipids. However, plasma lipid levels were much higher in Pekin ducks than in Muscovy ducks, suggesting a greater ability to export lipids from the liver. Values for the different criteria measured in this study were intermediate or similar in hinny and mule ducks to those of parental species. The high values for GK, G6PDH, ME and ACX activity in hybrid ducks enabled them to produce heavy fatty livers with the same chemical and lipid composition as Muscovy ducks and characterised by high amounts of triglycerides (around 96% of total lipids), and saturated and mono-unsaturated fatty acids.

Effect of genotype and overfeeding on lipid deposition in myofibres and intramuscular adipocytes of breast and thigh muscles of ducks.

We conducted a study to evaluate the effects of genotype (Muscovy, Pekin and their crossbred, hinny and mule) and overfeeding (14 days from 12 weeks of age) on lipid deposition in myofibres and intramuscular adipocytes of breast and thigh muscles of ducks. Birds of the four genotypes were also reared contemporaneously with a growing diet distributed ad libitum. Muscle samples (Pectoralis major and Sartorius) were collected at 14 weeks of age on 8 ducks per treatment. The muscle fibre typing, the total lipid and triglyceride contents in myofibres and the relative surface occupied by adipocytes on the cross-sectional area of the muscles were determined by histological and image analysis. Overfeeding induced a marked increase of body weight but had no significant effect on the muscle weight, the cross-sectional area (CSA) of myofibres and the muscle typology. In muscles, overfeeding induced a large accumulation of lipids, mainly in adipocytes whose relative surface increased 1.5 fold in P. major and 2.1 fold in Sartorius and an increase in triglyceride content of fast twitch oxydo-glycolytic and glycolytic fibres in P. major only (+ 37 and + 16% respectively). Genotype had no significant effect on the muscle typology. By comparison with the other genotypes, Muscovy ducks exhibited the highest body weight, the highest muscle weight which could partly be explained by the highest fibre CSA and the lowest intramuscular fat content in adipocytes and myofibres (only fast twitch oxydo-glycolytic fibres in P. major). We observed the reverse situation for the Pekin ducks. The crossbred ducks always presented intermediate values except for body weight.

Differential channelling of liver lipids in relation to susceptibility to hepatic steatosis in two species of ducks.

In the human, hepatic steatosis can be associated with an imbalance between synthesis, secretion and storage of hepatic lipids, and exhibits a genetic susceptibility. The effect of overfeeding on hepatic lipid channelling was investigated in two genotypes of ducks that differ in their susceptibility to fatty liver, i.e. the common duck, Anas platyrhynchos, and the Muscovy duck, Cairina moschata. Before overfeeeding, the Muscovy duck exhibited a lower subcutaneous adiposity and a higher muscular development, whereas hepatic composition was similar in both genotypes (>5% lipids and triglycerides accounting for 6-10% lipids). In the plasma lipoprotein profile, HDL predominated (5.5-7.8 g/l) over VLDL (0.09-0.25 g/l) and LDL (0.65-1.06 g/l). All lipid and lipoprotein concentrations were lower in the Muscovy duck. In response to overfeeding, the Muscovy duck exhibited a higher degree of hepatic steatosis (62 vs. 50% lipids), and a lower increase in adiposity and in the concentration of plasma triglycerides (6-fold vs. 10-fold) and VLDL (23-fold vs. 34-fold). Thus, certain genotypes may be more responsive to the dietary induction of fatty liver because of a less efficient channelling of hepatic lipids towards secretion into plasma and adipose storage, and the duck may represent a suitable model in which to study the development of hepatic steatosis and its pathogenesis.

Hormonal and metabolic responses to overfeeding in three genotypes of ducks.

Muscovy, Pekin and Mule duck are different in their body weight. To make a valid comparison in the lipid metabolism between these three genotypes, overfeeding was carried out by providing the animals with amounts of food in proportion to their body weight. Under these conditions, Muscovy ducks developed a strong liver steatosis, whereas it was not very pronounced in the Mule ducks and even less in the Pekin ducks. On the contrary, Pekin ducks showed a much marked extrahepatic fattening. At the beginning of overfeeding, there was a similarity in the three genotypes as regards the post-heparin lipoprotein-lipase (LPL) activity and the insulin and glucagon concentrations. After 10 days of overfeeding, the LPL activity dramatically fell in Muscovy and in Mule ducks, whereas it remained steady in Pekin ducks. Compared to values found at the beginning of the overfeeding period, plasma glucagon and insulin shown no evolution, except for the insulin of Pekin ducks which was dramatically higher. Those data suggest that high plasma insulin concentrations measured in Pekin ducks after 10 days of overfeeding can be responsible for the maintenance of the LPL activity, which favors the extrahepatic fattening to the detriment of liver steatosis.

The effects of overfeeding on myofibre characteristics and metabolical traits of the breast muscle in Muscovy ducks (Caïrina moschata).

The aim of this experiment was to study the consequences of precise feeding on the myofibre characteristics and metabolic traits of the breast muscle (Pectoralis major, Pm) of Muscovy ducks. Twenty-four samples of breast muscle, without skin or subcutaneous fat, from two groups of ducks, control and overfed respectively, were collected at 14 weeks of age. We assayed different chemical (water content, crude proteins, total lipid ashes, total and thermosoluble collagen), biochemical (activities of the CS, LDH and beta-HAD enzymes), histological (muscle fibre typing and intramuscular adipocyte measurements) and technological (drip and cooking losses, texture) determinations. At the force-feeding period, the overfed ducks weighed 6366 g and the control ducks 4606 g of body weight. In the PM muscle, some modifications of the biochemichal parameters and enzyme activities were observed but neither the shear force nor the histological characteristics of the breast muscle were affected by the fattening treatment. The overfed birds had an increased total lipids content (correlated to an increase in the intramuscular area occupied by the adipocyte) and a different fatty acid profile as the result of a higher energy feed intake. The lipids of the Pm muscle of the overfed ducks contained more C16:0, C16:1n-7 and C18:1n-9, but less C18:0, C18:2n-6 and C20:4n-6 than the control birds. These results show that in response to high energy feeding, the muscle is able to respond quickly on a metabolic basis (by increasing the activities of the oxydative enzymes) without changing its typology or morphology. Additionally, fattening was correlated to a degradation in the technological qualities of the breast muscle, especially an increase in the cooking losses.