The impact of compaction, moisture content, particle size and type of bulking agent on initial physical properties of sludge-bulking agent mixtures before composting

This study aimed to experimentally acquire evolution profiles between depth, bulk density, Free Air Space (FAS), air permeability and thermal conductivity in initial composting materials. The impact of two different moisture content, two particle size and two types of bulking agent on these four parameters was also evaluated. Bulk density and thermal conductivity both increased with depth while FAS and air permeability both decreased with it. Moreover, depth and moisture content had a significant impact on almost all the four physical parameters contrary to particle size and the type of bulking agent

Study of thermal conductivity in organic solid wastes before composting

In France, like in all developed countries, the amount of solid wastes generated per year has increased continuously since the 1960's. To hold back this trend, waste policies have been set up, as illustrated by current EU waste policy and its five main priorities: prevention, reuse, recycling, recovery and disposal. Composting can be defined as the process whereby aerobic micro-organisms convert organic substrates into compost: a hygienic, biostable product that can be beneficially applied to land (Haug, 1993; Mohee & Mudhoo, 2005). Therefore, it fits perfectly with the fourth priority, recovery, which fosters extraction of useful material or energy from wastes. In this context, interest towards composting has increased continuously during the last few years. During treatment, micro-organisms breakdown organic matter and produce carbon dioxide, water and heat. Heat generated by biological activity modifies moisture content and temperature conditions. These changes result in the appearance of a temperature peak in first days of treatment and most pathogens are killed by the high temperatures reached (around 70-80°C), turning waste into a hygienic product. Among the various physical parameters taking part in the composting process, thermal conductivity seems to be of major importance, and could be used as an indicator to follow heat transfers within the organic matrix. However, as all physical parameters involved in the process, the initial preparation of the substrate (adjustment of moisture content or C/N ratio, addition and mixing with bulking agent …) has an influence on the physical parameters involved in the process (such as bulk density, Free Air Space or air permeability) and thus, on thermal conductivity. Moreover, difficulties often occur in composting experiments because the effects of compaction on physical properties are ignored, or information about these effects is lacking. As soon as the pile of waste is built, the settlement of the composting matrix begins. This settlement, called primary settlement or physical compressive settlement (Gourc et al., 2010; Yue et al., 2008) is related to the vertical load and leads to compaction. Despite its major importance, until now little has been written on thermal conductivity in composting, in particular about its link with compaction. That's why this study focus on it and aims to investigate how it evolves with (i) compaction or depth within the pile of waste, (ii) preparation parameters of the substrate and (iii) temperature. This investigation was carried out on mixtures of urban sludge and wooden palettes used as bulking agents. To understand how preparation parameters of the mixtures would affect thermal conductivity, two moisture content (50 and 65%), two types (fresh and recycled) and two meshes of bulking agent ( 20 mm) were tested. The influence of compaction (or depth) was evaluated in two steps. First, a "Schaub-Szabo" device (strongly inspired by the apparatus described in Schaub-Szabo and Leonard (Schaub-Szabo & Leonard, 1999)) was used to get depth-bulk density profiles in the different substrates. Then, these bulk densities were recreated in a modified air pycnometer where thermal conductivity was measured with a thermal probe directly embedded in the composting sample. Therefore, a link between thermal conductivity and compaction (or depth) could be established. On the other hand, the study of the impact of temperature on thermal conductivity was carried out in 10 liter cells where biological activity was prevented by a nitrogen atmosphere. The cells were filled with the same eight sludge-wooden palettes mixtures as before, and a thermal probe was put directly inside each sample. Then, they were put in different constant-temperature baths with target temperature from 5 to 75°C. In this study, thermal conductivity increased with depth and a statistical analysis highlighted the fact that it was only significantly impacted by moisture content (among the three preparation parameters cited above). Moreover, the impact of temperature on thermal conductivity was clear and a linear relationship between these two parameters could be established. Each correlation was specific to the substrate but with a similar slope. These results are interesting in two ways: first, until now little has been written on thermal conductivity in organic solid wastes, and in particular about its link with compaction. Besides this originality, the data obtained can now be used in numerical modeling to get a more thorough and accurate way to model heat transfers, an essential part of modeling composting systems

Skin-to-skin transfer from the delivery room to the neonatal unit for neonates of 1,500g or above: a feasibility and safety study

ObjectiveImmediate skin-to-skin contact (SSC) is already standard care for healthy term newborns, but its use for term or preterm newborns requiring admission to neonatal intensive care unit (NICU) with or without respiratory support is challenging. This study aimed to assess the safety and feasibility of SSC during the transfer of newborn infants, using a new purpose-built mobile shuttle care-station, called “Tandem”.Material and methodsA monocentric prospective observational study was conducted at the tertiary referral center of the Université libre de Bruxelles in Brussels, Belgium after ethical approval by Hopital Erasme's Ethics Committee (ClinicalTrials.gov ID: NCT06198478). Infants born with a birth weight above 1,500 g were included. Following initial stabilization, infants were placed in SSC with one of their parents and transferred to the NICU using the Tandem.ResultsOut of 65 infants initially included, 64 (98.5%) were successfully transported via SSC using the Tandem. One transfer was not successful due to last minute parental consent withdrawal. The median (range) duration of continuous skin-to-skin contact after birth was 120 min (10–360). SSC transfers were associated with gradually decreasing heart rate (HR) values, stable oxygen saturation levels (SpO2), and no increase in median fraction of inspired oxygen (FiO2). Heatloss was predominantly observed during initial setup of SSC. There was no significant difference in the occurrence of tachycardia, desaturation or hypothermia between preterm and term neonates. No equipment failures compromising the transfer were recorded.ConclusionSkin-to-skin transfer of infants with a birthweight of equal or above 1,500 g using the Tandem shuttle is feasible and associated with stable physiological parameters. This method facilitates early bonding and satisfies parents.Clinical Trial RegistrationClinicalTrials.gov (NCT06198478)

Cadmium accumulation and interactions with zinc, copper, and manganese, analysed by ICP-MS in a long-term Caco-2 TC7 cell model

The influence of long-term exposure to cadmium (Cd) on essential minerals was investigated using a Caco-2 TC7 cells and a multi-analytical tool: microwave digestion and inductively coupled plasma mass spectrometry. Intracellular levels, effects on cadmium accumulation, distribution, and reference concentration ranges of the following elements were determined: Na, Mg, Ca, Cr, Fe, Mn, Co, Ni, Cu, Zn, Mo, and Cd. Results showed that Caco-2 TC7 cells incubated long-term with cadmium concentrations ranging from 0 to 10 lmol Cd/l for 5 weeks exhibited a significant increase in cadmium accumulation. Furthermore, this accumulation was more marked in cells exposed long-term to cadmium compared with controls, and that this exposure resulted in a significant accumulation of copper and zinc but not of the other elements measured. Interactions of Cd with three elements: zinc, copper, and manganese were particularly studied. Exposed to 30 lmol/l of the element, manganese showed the highest inhibition and copper the lowest on cadmium intracellular accumulation but Zn, Cu, and Mn behave differently in terms of their mutual competition with Cd. Indeed, increasing cadmium in the culture medium resulted in a gradual and significant increase in the accumulation of zinc. There was a significant decrease in manganese from 5 lmol Cd/l exposure, and no variation was observed with copper. Abbreviation: AAS – Atomic absorption spectrometry; CRM– Certified reference material; PBS – Phosphate buffered saline without calcium and magnesium; DMEM – Dubelcco’s modified Eagle’s medium

Synthèse de pyrroles diversement substitués, approche vers la synthèse d'un analogue hybride de la lavendamycine et de la camptothécine

Ce travail méthodologique en série pyrrolique s inscrit dans un projet de synthèse totale d un analogue hybride de la lavendamycine et de la camptothécine. Ces deux molécules sont toutes deux inhibitrices de topoisomérase de type I, ce qui leur confère des propriétés anticancéreuses. Cette recherche s inscrit donc parfaitement dans un des thèmes de recherche du laboratoire visant à synthétiser des nouvelles molécules présentant une activité biologique potentielle. La synthèse de cette nouvelle molécule passe par celle d un intermédiaire-clé à structure pyrrolique, qui permettra d atteindre la cible souhaitée par une réaction de Pictet-Spengler, déjà mise au point au laboratoire. Le travail de recherche a donc consisté à construire cet hétérocycle azoté 2,3,4-trisubstitué, d une part par une -hydroxy lactone accolée au cycle dans les positions 2 et 3, et d autre part par une chaîne amino-ester en position 4. Le premier chapitre présente les aspects méthodologiques de la synthèse de l intermédiaireclé, à savoir la construction de la lactone, l introduction de la chaîne amino-ester puis en dernier lieu la construction du pyrrole en fonction des substituants requis. Afin d obtenir l intermédiaire-clé pyrrolique, nous avons envisagé deux stratégies de construction. La première fait l objet du second chapitre, et envisage la synthèse à partir d un pyrrole 2,3,4- trisubstitué. Pour cela, nous avons tenté d introduire un troisième substituant sur un pyrrole 3,4-disubstitué obtenu via le TosMIC, par une réaction de type Vilsmeier-Haack. Ensuite, l insertion du carbone terminal du TosMIC dans une liaison carbone-halogène avant cyclisation pyrrolique a été tentée. Enfin, nous avons envisagé la synthèse à partir d un pyrrole 2,3,4-trisubstitué obtenu en une étape via le TosMIC, et présentant un groupement stannylé précurseur de groupe électrophile en position 3. Le troisième chapitre décrit la seconde stratégie qui envisage la construction de l intermédiaire-clé à partir d un pyrrole 3,4-disubstitué. Elle met en jeu une fermeture du cycle lactonique sur la position 2 du pyrrole lors de l ultime étape de la réaction. Pour cela, nous avons mis en jeu des réaction très variées comme une réaction de couplage de Stille ou une réaction d alkynylation de cétones pour permettre la fonctionnalisation de l accepteur de Michael avant cyclisation pyrrolique. Mais la voie la plus avancée a consisté à introduire les groupements fonctionnels après cyclisation pyrrolique, par une réaction de cyanosilylation et un allongement de la chaîne. Une ultime étape, inévitable, de déprotection de l azote du pyrrole aurait pu permettre d effectuer la fermeture de la lactone souhaitée.This methodological work on pyrrole compounds deals with an approach to a total synthesis of an hybrid analogue of lavendamycin and camptothecin. These two molecules, with antitumor activity, are both inhibitors of topoisomerase I. Thus, this study is connected with one of the laboratory s thematics, which is the synthesis of new molecules with potential biological activity. Our strategy for obtaining the hybride analogue includes the synthesis of a pyrrolic intermediate, as the key-step. Pictet-Spengler reaction, already used in our laboratory in related cases, would allow obtaining the target molecule. This work deals with the building of a 2,3,4-trisubstituted pyrrolic intermediate, on the one hand by via an -hydroxy lactone and on the other hand via an amino-ester chain. The first chapter is devoted to methodological aspects for synthesis of the key-intermediate : lactone building, amino-ester introduction and then pyrrole building, depending on the required substituents. Two strategies were investigated to obtain the pyrrolic key-intermediate. The first one is developped in the second chapter. A possibility to synthesize the suitable 2,3,4-trisubstituted pyrrole would be to firstly prepare a 3,4-disubstituted pyrrole from TosMIC and then to introduce the third substituant by a Vilsmeier-Haack reaction, and we examined it. We also tried to insert the terminal carbon of TosMIC in a carbone-halogen link. We equally prepared a 2,3,4-trisubstituted pyrrole with a stannylated group at 3 position and we examined the possibilities of replacing the latter by the desired group. The third chapter deals with the second strategy in which the target molecule would be obtained from a 3,4-disubstituted pyrrole with a precursor of the lactone moiety at 3 position, then to carry out an intramolecular cyclization reaction towards 2 position. Various reactions were examined such as Stille coupling or ketone alkynylations, in order to fonctionnalize the Michael acceptor before the pyrrolic cyclization. In the most advanced way, introduction of the fonctionnal groups were carried out after the pyrrolic cyclisation, by a cyanosilylation reaction followed by chain extension. The unavoidable last step, for the pyrrole nitrogen deprotection, should have led to the lactone.LE MANS-BU Sciences (721812109) / SudocSudocFranceF

Prise en charge des pneumopathies aiguës communautaires de l'adulte au Centre Hospitalier de Troyes. Etude prospective à propos de 64 cas

REIMS-BU Santé (514542104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Highly Sensitive and Specific Detection of Staphylococcal Enterotoxins SEA, SEG, SEH, and SEI by Immunoassay

International audienceStaphylococcal food poisoning (SFP) is one of the most common foodborne diseases worldwide, resulting from the ingestion of staphylococcal enterotoxins (SEs), primarily SE type A (SEA), which is produced in food by enterotoxigenic strains of staphylococci, mainly S. aureus. Since newly identified SEs have been shown to have emetic properties and the genes encoding them have been found in food involved in poisoning outbreaks, it is necessary to have reliable tools to prove the presence of the toxins themselves, to clarify the role played by these non-classical SEs, and to precisely document SFP outbreaks. We have produced and characterized monoclonal antibodies directed specifically against SE type G, H or I (SEG, SEH or SEI respectively) or SEA. With these antibodies, we have developed, for each of these four targets, highly sensitive, specific, and reliable 3-h sandwich enzyme immunoassays that we evaluated for their suitability for SE detection in different matrices (bacterial cultures of S. aureus, contaminated food, human samples) for different purposes (strain characterization, food safety, biological threat detection, diagnosis). We also initiated and described for the first time the development of monoplex and quintuplex (SEA, SE type B (SEB), SEG, SEH, and SEI) lateral flow immunoassays for these new staphylococcal enterotoxins. The detection limits in buffer were under 10 pg/mL (0.4 pM) by enzyme immunoassays and at least 300 pg/mL (11 pM) by immunochromatography for all target toxins with no cross-reactivity observed. Spiking studies and/or bacterial supernatant analysis demonstrated the applicability of the developed methods, which could become reliable detection tools for the routine investigation of SEG, SEH, and SEI

Reflections on the future developments of research in retrospective physical dosimetry

Electron paramagnetic resonance, thermoluminescence, and optically stimulated luminescence, with biological tissues and inert materials are well established physical methods for retrospective dosimetry in acute accidental exposures. The objective of this article is to provide a view of the questions still open, the current challenges and the needed solutions. As research on emergency response methods is encountering increasing difficulties in terms of financial and human resources in many countries, it is essential to identify the research priorities and pay attention to cost-effective research paths. The intention of the paper is to stimulate discussion in the scientific community and to encourage collaboration among laboratories toward goals that address the real needs in retrospective dosimetry for acute exposures