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Molecular Simulations of Polymer‐based Drug Nanocarriers: From Physical and Structural Properties to Controlled Release
No full textInternational audiencePolymer‐based drug delivery systems have been extensively studied to overcome the limitations of free drug administration (e.g., poor solubility and stability, rapid degradation and early metabolization, short plasma half‐life, low therapeutic efficacy, and occurrence of side effects). Although the vast majority of these drug delivery systems are developed using the traditional time‐ and resource‐intensive trial‐and‐error method, computational techniques have received considerable attention in order to facilitate and accelerate their understanding and development. In this review, several computational techniques is presented that are commonly used to study polymer‐based drug delivery systems. Then, this is discussed several computational investigations of the self‐assembly and supramolecular organization of polymer nanocarriers for drug delivery applications, including drug‐loaded polymer micelles and polymer prodrug nanoparticles. How modeling approaches can rationalize the drug loading and release from polymer drug delivery systems is further examined, including studies which aim to better understand how physical, chemical, or biological stimuli can trigger the drug release. Machine learning possibilities for extending physics‐based molecular simulation efficiency and predictive power have also been briefly discussed
Présentation de madbot au BioStream
No full textInternational audiencemadbot (Metadata And Data Brokering Online Tool) is a web application that provides a dashboard for managing research data and metadata. Madbot aims to support biologists in handling and publishing their data and metadata while adhering to best practices in the field. This includes raising awareness of and ensuring compliance with the FAIR principles (Findable, Accessible, Interoperable, and Reusable).madbot (Metadata And Data Brokering Online Tool) est une application web qui fournit un tableau de bord pour la gestion des données et des métadonnées de recherche. Madbot a comme objectif d’accompagner les biologistes dans la gestion et la publication de leurs données et métadonnées, en conformité avec les bonnes pratiques en la matière. Cela inclut une sensibilisation et un respect des principes FAIR (Facile à trouver, Accessible, Interopérable et Réutilisable)
Synthesis and Evaluation of the First Generation of Glycosylated Nucleoside Analogues as Potential Inhibitors of the Base J Metabolism in Kinetoplastid Parasites
No full textInternational audienceLeishmaniasis and trypanosomiasis are severe parasitic infections with significant impacts on veterinary and public health, particularly affecting the poorest populations. The therapeutic arsenal against these neglected tropical diseases is limited, and the emergence of resistance to available medicines complicates treatment. These kinetoplastid parasites share a unique DNA modification, that is β‐ d ‐glucosyl‐5‐hydroxymethyluracil (base J), which appears to play an essential role in parasite development and survival through an original epigenetic mechanism, allowing adaptation to environmental changes. To date, the regulatory pathway of this unique nucleobase has not been explored as a potential therapeutic target. In this work, we report the synthesis of several families of base J analogues and assess their potential against different kinetoplastid species. Some compounds have shown antiparasitic activity and no toxicity toward human primary fibroblasts, revealing promising new strategies for antiparasitic therapy
Cosmoglobe DR2. IV. Modelling starlight in DIRBE with Gaia and WISE
No full textInternational audienceWe present a model of starlight emission in the Diffuse Infrared Background Explorer (DIRBE) data between 1.25 and 25m based on \textit{Gaia} and WISE measurements. We include two classes of compact objects, namely bright stars with individual spectral energy densities (SEDs) measured by \textit{Gaia}, and a combined diffuse background of dim point source emission. Of the 424 829 bright sources that we fit, the number of stars with a flux density detected by WISE at Galactic latitudes at more than is 94 680, for an average of 1.36~stars per DIRBE beam area. For each star, we adopt physical parameters (, , and [M/H]) from \textit{Gaia}; use these to identify a best-fit effective SED with the PHOENIX stellar model library; convolve with the respective DIRBE bandpass; and fit an overall free amplitude per star within the Bayesian end-to-end \texttt{Cosmoglobe} DR2 framework. The contributions from faint sources are accounted for by coadding all 710 825 587 WISE sources not included as bright stars, and fit one single overall amplitude per DIRBE band. Based on this model we find that total star emission accounts for 91 % of the observed flux density at 2.2 m; 54 % at 4.9m; and 1 % at 25 m. As shown in companion papers, this new model is sufficiently accurate to support high-precision measurements of both the Cosmic Infrared Background monopole and zodiacal light emission in the three highest DIRBE frequencies
Cosmoglobe DR2. VII. Towards a concordance model of large-scale thermal dust emission for microwave and infrared frequencies
No full textInternational audienceWe fit a four-component thermal dust model to COBE-DIRBE data between 3.5 and 240 micron within the global Bayesian end-to-end Cosmoglobe DR2 reanalysis. Following a companion analysis of Planck HFI, the four components of this model correspond to "hot dust", "cold dust", "nearby dust", and "Halpha correlated dust", respectively, and each component is modelled in terms of a fixed spatial template and a spatially isotropic spectral energy density (SED) defined by an overall free amplitude for each DIRBE channel. Except for the cold dust amplitude, which is only robustly detected in the 240 micron channel, we measure statistically significant template amplitudes for all components in all DIRBE channels between 12 and 240 micron. In the 3.5 and 4.9 micron channels, only the hot component is detected, while the 1.25 and 2.2 micron channels are too dominated by starlight emission to allow robust dust detections. The total number of DIRBE-specific degrees of freedom in this model is 25. Despite this low dimensionality, the resulting total SED agrees well with recent astrodust predictions. At both low and high frequencies, more than 95 % of the frequency map variance is captured by the model, while at 60 and 100 micron about 70 % of the signal variance is successfully accounted for. The hot dust component, which in a companion paper has been found to correlate strongly with C ii emission, has the highest absolute amplitude in all DIRBE frequency channels; in particular, at 3.5 micron, which is known to be dominated by polycyclic aromatic hydrocarbon emission, this component accounts for at least 80 % of the total signal. This analysis represents an important step towards establishing a joint concordance model of thermal dust emission applicable to both the microwave and infrared regimes
μRWELL-PICOSEC: Precision Timing with Resistive Micro-Well Detector
No full textInternational audienceThe PICOSEC detector concept uses a micro-pattern gaseous detector (MPGD) amplification structure combined with a Cerenkov radiator coated with a semi-transparent photocathode to provide below tens of picosecond-level precision timing capabilities with minimum ionizing particles. PICOSEC has triggered interest in the development of time-of-flight detectors for particle identification and timing detectors for track reconstruction in the high rate environment of future nuclear and high energy physics experiments. The PICOSEC Micromegas (or PICOSEC-MM) detector, developed by the CERN-based PICOSEC collaboration, use the Micromegas structure for gaseous amplification and achieve below 20 ps timing resolution. A new type of PICOSEC detector, the μRWELL-PICOSEC based on μRWELL amplification structure, is being investigated at Thomas Jefferson National Accelerator Facility (Jefferson Lab) alongside PICOSEC-MM R&D efforts in Europe. Preliminary results from the two 2024 beam test campaigns at CERN demonstrate a timing performance better than 24 ps is achievable with a single-channel μRWELL-PICOSEC prototype. A vigorous R&D effort is ongoing to improve the timing performance, robustness and operational stability of μRWELL-PICOSEC detectors. Development of a large size μRWELL-PICOSEC is also under consideration for applications in large scale experiments
Bioinspired bi- or trinuclear FeMoS model complexes for the partial region of FeMo cofactor of nitrogenase
No full textInternational audienceSulfur-rich {FeMo} complexes of low nuclearity ({Fe2Mo}, {FeMo}) can be considered as simple truncated models of the cofactor of Mo‑nitrogenase. They are suitable to address questions concerning the role of the still unclear FeMo cooperativity in the biological N2-reduction process performed by this metallo-enzyme. This review affords a state of the art of the chemistry of di- and tri-heterometallic {FeMoS} complexes. Although well-defined synthetic procedures have been evidenced for the design of such compounds, very few investigations on their activity towards N2 and related substrates have been reported. This shows the interest to develop new light bio-inspired {FeMoS} molecules and to study their reactivity, as well as their redox behaviours, to help to better understand the biological N2-fixation. This approach involving di- and tri- heterometallic {FeMoS} species is a promising field of investigation
Improving electrochemical aptasensor sensitivity for Bacillus cereus spore detection in food safety applications
No full textInternational audienceRapid detection of Bacillus cereus spores is essential for preventing food contamination and spoilage. Many existing methods detect B. cereus vegetative cells rather than spores and cannot be applied directly to foods. Here, we present a combination of aptamers targeting different moieties on the surface of B. cereus spores with rapid electrochemical detection. When DNA aptamers, previously selected for B. cereus spores, were immobilized on screen-printed gold electrodes, they exhibited higher binding capacity than individual aptamers, suggesting a synergistic effect. Additionally, the mixture of rhodamine-labelled aptamers enabled spatial fluorescent visualization of the B. cereus endospore structure, confirming the increased binding efficiency. The electrochemical aptasensor based on three aptamers exhibited a wide dynamic range (102–107 CFU/mL) and low limit of detection (∼1 CFU/mL) using just 15 μL of sample. Validation in spiked salad, using direct spore sensing in rinse water and comparison with the culturing method, confirmed its sensitivity and specificity. These combined aptamer approaches, achieving rapid (15 min) and single-step detection may also be suitable for detecting other foodborne pathogens
Evidence of Fukushima fallout in the area affected by wildfires in Kamaishi (Iwate Prefecture, Tohoku Region, Japan): Implications for future environmental research using radionuclide tracers
No full textInternational audienceSignificant deposition of radiocesium including 134Cs and 137Cs occurred in March 2011 following the Fukushima nuclear accident across vast regions of Northeastern Japan. However, as most studies focused on fallout that took place in the Fukushima Prefecture, much less information is available on the situation that prevails further to the North, in other parts of the Tohoku Region of Japan. In this context, the current research investigated the occurrence of fallout radionuclides (including natural 210 Pb-xs as well as artificial 134Cs and 137Cs) in burned and unburned soil profiles as well as in a range of surface soil and sediment samples collected in the region of Kamaishi (Iwate Prefecture, Tohoku Region, Japan) affected by wildfires in 2017. Results show that 210Pb-xs and 137Cs may be used as tracers of sediment sources across landscapes affected by wildfires in this region. Furthermore, the soil profile analysis demonstrated that all analysed fallout radionuclides were found enriched in the burned vs. unburned profiles, due to the incorporation of radionuclides trapped by vegetation into the ash after the fire. The detection of 134 Cs in the uppermost 0-5 cm depth layer in all investigated soil profiles also allowed to demonstrate the occurrence of significant Fukushima fallout of 134Cs and 137Cs in this region (roughly of the same order of magnitude as the fallout associated with the nuclear atmospheric tests in the 1960s). In the future, both sources of fallout should be considered to provide relevant interpretations when examining radionuclide data found in environmental samples collected in vast regions of Northeastern Japan. The analysis of 134Cs should also be encouraged to document the sources of fallout in these regions as long as this short-lived radionuclide remains detectable (i.e., theoretically by 2031)
Building pangenomes for domesticated and wild tree species: genomic complexity and strategies
No full textLong-read sequencing and pangenomics are revolutionizing crop research by providing more complete genome information and revealing crucial structural variations linked to important agricultural traits. Building on recent advances in intraspecific pangenome construction, this study addresses the challenge of creating broader, cross-taxon pangenomes, using the Armeniaca taxonomic section as a model. Leveraging a diverse panel of genome assemblies, we constructed a pangenome graph and cataloged associated single nucleotide polymorphisms (SNPs) and structural variants. We characterized the diversity of these variants and assessed the extent to which different taxa contribute to overall pangenome expansion. Additionally, we evaluated the performance of low-depth sample mapping to the graph-based reference, highlighting key technical limitations that may affect the quality of downstream analyses. We further identified specific subsets of SVs that exhibit associations with particular classes of transposable elements. As a case study illustrating the potential functional and phenotypic relevance of graph-derived SVs, we examined the genomic configuration of the DAM locus within the Armeniaca pangenome