Georges Friedel Laboratory

Hydrate-based technologies are the new topics in the hydrate community with many industrial applications. Recently, gas hydrate-based desalination (HBD) is considered as a novel and potential solution for water treatment. The gas hydrate-based desalination process will be promoted with higher hydrate formation rate and lower operating pressure in the presence of promoters. In this work, Cyclopentane (CP) is used as a hydrate promoter for CO2 hydrate-based desalination process. The main purpose of this research is to obtain the kinetic data of mixed CP−CO2 hydrates in the presence of sodium chloride with 3.5 wt.%. The experimental data for mixed CP−CO2 hydrates in the presence of sodium chloride are obtained in a batch reactor system with a temperature range of 2.3÷10.7 oC and a pressure range of 23÷33 bars. The effects of temperature, pressure, agitation speed and amount of CP on kinetics of mixed CP−CO2 hydrate formation are also reported. This research would provide the new data to progress the hydrate-based desalination and water treatment.

For the past 30 years, nanoindentation has provided critical insights into the microstructure–strength relationship for a wide range of materials. However, it has traditionally been limited to quasistatic testing at room temperature, which has hindered a holistic understanding of microstructurally induced deformation mechanisms and their dynamic evolution as a function of the temperature and strain rate. Over the past decade, the operational scope of nanoindentation has expanded dramatically. Temperatures up to 1100°C and strain rates as high as 10+4 s−1 and as low as 10−8 s−1 have become accessible. In addition, advanced techniques allow tracking microstructural evolution and corresponding changes in mechanical behavior during deformation under extreme conditions. These advancements have transformed nanoindentation into a versatile tool for comprehensive materials characterization, enabling high-throughput investigations under multimodal conditions.Graphical abstract

Abstract Over the past 20 years, endothelial keratoplasty procedures have revolutionized the treatment of corneal endothelial disorders. These conditions have now become the leading indication for corneal transplantation in Western countries and account for half of all donor cornea usage. Despite their undeniable success, the global shortage of donor tissues and major disparities between nations justify the development of alternatives to donor grafts. Cell therapy using injections of suspended endothelial cells has proven effective, and tissue-engineered endothelial keratoplasty (TEEK) comprising a membrane coated with cultured endothelial cells is under development to better mimic the native endothelial graft. Our team utilizes a femtosecond-laser-cut lens capsule disc as a bioengineering scaffold, taking advantage of this novel tissue’s biocompatibility, transparency, curvature, and availability. In the present study, we provide proof of concept, in 12 TEEKs, that it is possible to control the final endothelial cell density (ECD) by varying the seeding density per mm2. Cell characterization was performed through morphometric analysis of the endothelial mosaic stained with anti-NCAM (a lateral membrane marker used as a differentiation marker), using the CellPose artificial intelligence algorithm specifically trained for in vitro endothelium segmentation. Five criteria related to pleomorphism, polymorphism, and elongation were combined into a single endothelial quality score. The median cell viability at 28 days of culture, assessed by Hoechst 33342 and Calcein-AM staining, reached 98% (range: 83–99%). The median viable ECD (number of live cells per surface unit) in the highest-density group was 3,245 cells/mm2(range: 2,778–3,753), paving the way for the bioengineering of supra-physiological TEEKs, or super TEEKs.Impact statementThe process of manufacturing tissue-engineered endothelial keratoplasty (TEEK) allows for the control of endothelial cell density (DCE) and, in particular, the creation of super TEEKs, meaning grafts with supra-physiological DCE that are more likely to better withstand the challenges of surgery and have a prolonged lifespan in recipients.

Drug hypersensitivity reactions to essential antibiotics like vancomycin pose significant diagnostic and therapeutic challenges, particularly in vulnerable populations such as pediatric patients with immune deficiencies. We present the case of a 7-year-old girl with primary immunodeficiency who experienced immediate hypersensitivity reactions to vancomycin, including urticaria and angioedema, managed with corticoids and antihistamines. The Basophil Activation Test (BAT) conducted two years after the last allergic episode revealed significant basophil activation across all tested vancomycin dilutions, with CD63 and CD203c expression exceeding negative and positive controls. These findings confirm vancomycin hypersensitivity and underscore the BAT's utility as a reliable in vitro diagnostic tool, especially in settings where skin testing or specific IgE assays are unavailable. This case highlights the BAT's potential for broader adoption in clinical allergy practice, particularly in resource-limited environments. It emphasizes the importance of reliable diagnostic methods for managing drug hypersensitivity in high-risk patients.

Understanding material structural reaction to light is of utmost importance to advance processing resolution in ultrafast laser volume structuring into the nanoscale. Selective thermodynamic pathways are required to quench energy transport in the most rapid manner and to confine the process to nanometer lengths, bypassing optical resolution. Quantifying material dynamics under confinement, with in situ access to transient local temperature and density parameters, thus becomes key in understanding the process. We report in situ reconstruction of thermodynamic states over the entire matter relaxation path in bulk α -quartz irradiated by ultrafast nondiffractive laser beams using time-resolved qualitative and quantitative optical phase microscopy. Thermooptic dynamics indicate rapid spatially confined crystalline-to-amorphous transition to a hot dense fused silica form. Densification exceeds 20% and the matrix temperature rises to more than 2,000 K in the first nanosecond. This structural state relaxes in hundreds of nanoseconds. The dispersion and time design of the optical beam to picosecond durations increases the spatial confinement and triggers an extreme nanostructuring process based on nanocavitation that occurs within the amorphizing material, where the low-viscosity phase lowers the mechanical requirements for the process. Processing feature scales of less than a tenth of the optical wavelength are obtained in the volume. This allows for structural and morphological nanoscale material features under 3D confinement that can engineer optical materials.

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Experiments are conducted in water films falling along the bottom wall of a weakly inclined rectangular channel of height$5$mm in the presence of a laminar counter-current air flow. Boundary conditions have been specifically designed to avoid flooding at the liquid outlet, thus allowing us to focus on the wave dynamics in the core of the channel. Surface waves are excited via coherent inlet forcing before they come into contact with the air flow. The effect of the air flow on the height, shape and speed of two-dimensional travelling nonlinear waves is investigated and contrasted with experiments of Kofman, Mergui & Ruyer-Quil (Intl J. Multiphase Flow, vol. 95, 2017, pp. 22–34), which were performed in a weakly confined channel. We observe a striking difference between these two cases. In our strongly confined configuration, a monotonic stabilizing effect or a non-monotonic trend (i.e. the wave height first increases and then diminishes upon increasing the gas flow rate) is observed, in contrast to the weakly confined configuration where the gas flow is always destabilizing. This stabilizing effect implies the possibility of attenuating waves via the gas flow and it confirms recent numerical results obtained by Lavalleet al.(J. Fluid Mech., vol. 919, 2021, R2) in a superconfined channel.

The Riesz transform of u u : S ( R n ) → S ′ ( R n ) \mathcal {S}(\mathbb {R}^n) \rightarrow \mathcal {S’}(\mathbb {R}^n) is defined as a convolution by a singular kernel, and can be conveniently expressed using the Fourier transform and a simple multiplier. We extend this analysis to higher order Riesz transforms, i.e. some type of singular integrals that contain tensorial polyadic kernels and define an integral transform for functions S ( R n ) → S ′ ( R n × n × … n ) \mathcal {S}(\mathbb {R}^n) \rightarrow \mathcal {S’}(\mathbb {R}^{ n \times n \times \dots n}) . We show that the transformed kernel is also a polyadic tensor, and propose a general method to compute explicitely the Fourier mutliplier. Analytical results are given, as well as a recursive algorithm, to compute the coefficients of the transformed kernel. We compare the result to direct numerical evaluation, and discuss the case n = 2 n=2 , with application to image analysis.