Université Bordeaux-I

A pump‐probe shadowgraphy study of femtosecond laser percussion drilling on glass samples is reported applying three different operating regimes, which are the standard repetitive single pulse, the MHz‐ and the GHz‐burst modes. The comparison of pump‐probe imaging in the MHz‐burst and the GHz‐burst regimes is demonstrated for the first time to the best of knowledge. Synchronizing a single pulse probe with a pump operating in a burst regime constitutes a real novelty in femtosecond laser micromachining studies. By this means, a better understanding of the drilling process dynamics of the two burst regimes is provided and reveals the differences between these regimes. Especially, the process of through via drillings of different hole depths in the GHz‐burst regime is investigated in sodalime glass. The results of the pump‐probe shadowgraphy show that the ablation plume in the GHz‐burst regime has an essential role in the drilling process as it stops as soon as the plume escapes from the through hole explaining the final hole morphology observed for deep through via drillings.

We consider the Dirichlet-to-Neumann operator ${\mathcal {N}}$ associated with a general elliptic operator $\begin{aligned} {\mathcal {A}}u = - \sum _{k,l=1}^d \partial _k (c_{kl}\, \partial _l u) + \sum _{k=1}^d \Bigg ( c_k\, \partial _k u - \partial _k (b_k\, u) \Bigg ) +c_0\, u \in {\mathcal {D}}'(\Omega ) \end{aligned}$with possibly complex coefficients. We study three problems: (1) Boundedness on $C^\nu$ and on $L_p$ of the commutator $[{\mathcal {N}}, M_g]$, where $M_g$ denotes the multiplication operator by a smooth function g. (2) Hölder and $L_p$-bounds for the harmonic lifting associated with ${\mathcal {A}}$. (3) Poisson bounds for the heat kernel of ${\mathcal {N}}$. We solve these problems in the case where the coefficients are Hölder continuous and the underlying domain is bounded and of class $C^{1+\kappa }$ for some $\kappa > 0$. For the Poisson bounds we assume in addition that the coefficients are real-valued. We also prove gradient estimates for the heat kernel and the Green function G of the elliptic operator with Dirichlet boundary conditions.

Parkinson’s disease arises from the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to motor symptoms such as akinesia, rigidity, and tremor at rest. The non-motor component of Parkinson’s disease includes increased neuropathic pain, the prevalence of which is 4 to 5 times higher than the general rate. By studying a mouse model of Parkinson’s disease induced by 6-hydroxydopamine, we assessed the impact of dopamine depletion on pain modulation. Mice exhibited mechanical hypersensitivity associated with hyperexcitability of neurons in the dorsal horn of the spinal cord (DHSC). Serotonin (5-HT) levels increased in the spinal cord, correlating with reduced tyrosine hydroxylase (TH) immunoreactivity in the nucleus raphe magnus (NRM) and increased excitability of 5-HT neurons. Selective optogenetic inhibition of 5-HT neurons attenuated mechanical hypersensitivity and reduced DHSC hyperexcitability. In addition, the blockade of 5-HT 2A and 5-HT 3 receptors reduced mechanical hypersensitivity. These results reveal, for the first time, that PD-like dopamine depletion triggers spinal-mediated mechanical hypersensitivity, associated with serotonergic hyperactivity in the NRM, opening up new therapeutic avenues for Parkinson’s disease-associated pain targeting the serotonergic systems.

In this paper, we report on the full classification of generic iso-edge subdivisions of six-dimensional translational lattices. We obtain a complete list of 55083357 affine types of iso-edge subdivisions. We report on the use of the method of canonical forms that allows us to apply hashing techniques used in modern databases.

This work addresses the structural quantification of multiphase materials, here nanostructured polymer solid precursors and their micro/nano sized foamed counterparts. It is based on a strategy of contrast/edge enhancement, locally adaptive to image data in digital images of materials. The method allows to binarize straightforwardly the structures (the phases) in TEM and SEM images after edge identification, edge choice, and image virtual reconstruction. A detailed insight is brought into one‐step batch supercritical CO2 foaming of acrylic amorphous PMMA (polymethyl methacrylate) polymers, aided by the nanostructuration of block copolymers (BCP), here MAM (butyl acrylate center block methyl acrylate side blocks). The foaming conditions, i.e., pressure drop rate (PDR) and saturation temperature required for an actual one‐step procedure are specified and clarified, whereas previous works, dealing with “one‐step procedures”, are probably incurring in a two‐step procedure. The roles of the BCP content (and size) and saturation temperature are carefully analyzed and further clarified, more comprehensively than in previous literature. Thanks to the analysis of size distributions of foams and foam blend precursors (0.25, 0.5, 10 wt% MAM), bi modality of 10 wt% foams is for example revealed. A discussion of kinetics effects, i.e., evolutions of the effective sample temperature Tef(t), and the effective glass transition temperature Tg, ef(t). provides a new insight of “pseudo” one‐step VS “real” one‐step batch foaming.

During the cooking, processing, and storage of food products, a whole range of browning reactions occurs, initiated by the reaction of a carbohydrate with a compound possessing a free amino group. Melanoidins formed, influence food quality, mainly their colour, their flavour, and their antioxidant activities. Melanoidins are complex Maillard reaction products. We developed a method to isolate coffee melanoidins and melanoidins from toasted oak wood. We noted that coffee is richer in melanoidin compounds than oak wood. We presented a partial characterization of melanoidins fractions from toasted oak heartwood, and a comparison with melanoidins from roasted coffee. Mass spectra of the fractions isolated from toasted oak wood indicate the presence of pentose and hexose-based oligosaccharides with different degrees of polymerisation. The presence of the oligosaccharide moieties, as well as their degradation products found in the oak wood melanoidins, supports the postulated carbohydrate-based origin of melanoidins.

Among strategies to limit ischemia/reperfusion (IR) injuries in transplantation, cell therapy using stem cells to condition/repair transplanted organs appears promising. We hypothesized that using a cell therapy based on extracellular vesicles (EVs) derived from urine progenitor cells (UPCs) during hypothermic and normothermic machine perfusion can prevent IR‐related kidney damage. We isolated and characterized porcine UPCs and their extracellular vesicles (EVs). Then these were used in an ex vivo porcine kidney preservation model. Kidneys were subjected to warm ischemia (32 min) and then preserved by hypothermic machine perfusion (HMP) for 24 h before 5 h of normothermic machine perfusion (NMP). Three groups were performed (n = 5–6): Group 1 (G1): HMP/vehicle + NMP/vehicle, Group 2 (G2): HMP/EVs + NMP/vehicle, Group 3 (G3): HMP/EVs + NMP/EVs. Porcine UPCs were successfully isolated from urine and fully characterized as well as their EVs which were found of expected size/phenotype. EVs injection during HMP alone, NMP alone, or both was feasible and safe and did not impact perfusion parameters. However, cell damage markers (LDH, ASAT) were decreased in G3 compared with G1, and G3 kidneys displayed a preserved tissue integrity with reduced tubular dilatation and inflammation notably. However, renal function indicators such as creatinine clearance measured for 5 h of normothermic perfusion or NGAL perfusate's level were not modified by EVs injection. Regarding perfusate analysis, metabolomic analyses and cytokine quantification showed an immunomodulation signature in G3 compared with G1 and highlighted potential metabolic targets. In vitro, EVs as well as perfusates from G3 partially recovered endothelial cell metabolic activity after hypoxia. Finally, RNA‐seq performed on kidney biopsies showed different profiles between G1 and G3 with regulation of potential IR targets of EVs therapy. We showed the feasibility/efficacy of UPC‐EVs for hypothermic/normothermic kidney conditioning before transplantation, paving the way for combining machine perfusion with EVs‐based cell therapy for organ conditioning. Highlights ·UPCs from porcine urine can be used to generate a cell therapy product based on extracellular vesicles (pUPC‐EVs). ·pUPC‐EVs injection during HMP and NMP decreases cell damage markers and has an immunomodulatory effect. ·pUPC‐EVs‐treated kidneys have distinct biochemical, metabolic, and transcriptomic profiles highlighting targets of interest. ·Our results pave the way for combining machine perfusion with EV‐based cell therapy for kidney conditioning.

This paper presents a survey and critical analysis of the mathematical literature on modeling of dynamic populations living in a fluid medium. The present review paper is divided into two main parts: The first part deals with the multiscale derivation of deterministic and stochastic cross-diffusion systems governed by the incompressible Navier–Stokes equations. The derivation is obtained from the underlying description at the microscopic scale in kinetic theory models according to the micro–macro decomposition method. In the second part of this review, we are delighted to present a new variety of mathematical models describing different applications, namely, the pursuit–evasion dynamics, cancer invasion, and virus dynamics. Finally, critical analysis and future research perspectives are discussed.

Using ab initio molecular dynamics (AIMD) simulations, based on density functional theory that also accounts for van der Waals interactions, we study the oxidation of gas-phase CO on MoSe2 with a Se vacancy and oxygen coverage of 0.125 ML. In the equilibrium configuration, one of the O atoms is adsorbed on the vacancy and the other one atop one Se atom. Recombination of the CO molecule with the second of these O atoms to form CO2 is a highly exothermic reaction, with an energy gain of around 3 eV. The likeliness of the CO oxidation reaction on this surface is next examined by calculating hundreds of AIMD trajectories for incidence energies that suffice to overcome the energy barriers in the entrance channel of the CO oxidative recombination. In spite of this, no CO2 formation event is obtained. In most of the calculated trajectories, the incoming CO molecule is directly reflected, and in some cases, mainly at low energies, the molecules remain trapped at the surface but without reacting. As an important conclusion, our AIMD simulations show that the recombination of CO molecules with adsorbed O atoms is a very unlikely reaction in this system, despite its large exothermicity.

Introduction In 2021, among French women who smoked when they knew they were pregnant, 59% still smoked at the end of pregnancy. Support for pregnant women to stop smoking must include a structured organisational perspective. The main objective of the study is to evaluate the effectiveness of the 5A-QUIT-N organisational intervention on smoking cessation at delivery among pregnant women who smoke during pregnancy. Methods and analysis The overarching goal of the 5A-QUIT-N intervention, which aims to organise the healthcare professionals monitoring pregnancy, specialists in addiction and tobacco use, and clinical and training tools, using the 5As method. The 5A-QUIT-N intervention will be evaluated in a pragmatic stepped-wedge cluster randomised trial. Within each cluster, during the 6 months before (control) and after (intervention) the intervention, women who smoke tobacco during pregnancy will be enrolled during their maternity stay after delivery. A transition period is planned between the control and intervention periods to deploy the intervention. All participating women will be interviewed using a heteroquestionnaire to assess smoking cessation, tobacco use monitoring by healthcare professionals and individual factors associated with tobacco use during pregnancy. The primary outcome was the point prevalence of abstinence at delivery, which is the proportion of women reporting abstinence from smoking for at least 7 days at delivery. 4200 women who smoked tobacco during pregnancy will be recruited over the entire study period (33 months) to evaluate the effectiveness. An estimated 4585 participants will be included for all aims. Ethics and dissemination The study will be implemented in accordance with French regulations. The study including the consent process has been independently reviewed and approved by the French ethical board ‘CPP Ile de France I’ on 10 February 2022 (No CPPIDF1-2022-DI08-cat.2). The results will be disseminated on various academic and non-academic platforms. The results will be reported in international peer-reviewed journals and presented at international and national conferences.

We investigate the elongated modifications resulting from a Bessel beam-shaped femtosecond laser in fused silica under three different operation modes, i.e., the single-pulse, MHz-burst, and GHz-burst regimes. The single-pulse and MHz-burst regimes show rather similar behavior in glass, featuring elongated and slightly tapered modifications. Subsequent etching with Potassium Hydroxide exhibits an etching rate and selectivity of up to 606 μm/h and 2103:1 in single-pulse operation and up to 322 μm/h and 2230:1 in the MHz-burst regime, respectively. Interestingly, in the GHz-burst mode, modification by a single burst of 50 pulses forms a taper-free hole without any etching. This constitutes a significant result paving the way for chemical-free, on-the-fly drilling of high aspect-ratio holes in glass.

Objective The purpose was to analyze how rod characteristics, screw density and cages influence the incidence of mechanical complications compared to patient-related factors and alignment in adult spinal deformity instrumented T9-T11 to pelvis. Methods Register data of 302 patients was analyzed. Relative lumbar lordosis (RLL) and relative sagittal alignment (RSA) was measured. Surgical data included rod characteristics, pedicle screw density and interbody cages. Univariate and multivariate logistic regression models were used. Results Pseudarthrosis occurred in 24.1%. On univariate analysis Odds Ratio (OR) was 0.74 for ≥ 3 cages (p = 0.452), 0.48 for 4 rods (p = 0.008), 4.30 for high screw density (p = 0.001). Patient-related factors were non-significant. Multivariate OR was 0.59 for 4 rods (p = 0.084) and 4.67 for high screw density (p = 0.005). PJK/PJF occurred in 19.2%. Age > 60 had an OR 2.83 (p = 0.023), postoperative RSA malaligned OR 2.84 (p = 0.030), severely malaligned OR 6.54 (p < 0.001). Implant characteristics were non-significant. Multivariate OR was 1.26 for age > 60 (p = 0.657), 2.32 for malaligned RSA (p = 0.097), 5.69 for severely malaligned RSA (p = 0.001). Screw loosening occurred in 8.9%. Univariate OR was 0.95 for ≥ 3 cages (p = 0.920), 1.64 for 4 rods (p = 0.235), 0.25 for high screw density 1.5–2 (p = 0.011). Patient-related factors were non-significant. Multivariate OR for high screw density was 0.23 (p = 0.022). Conclusion Four rods decrease the pseudarthrosis risk. Cages have a secondary role. High screw density doesn’t prevent from pseudarthrosis. Postoperative malalignment is the main PJK/PJF risk factor. Age plays a secondary role. Implant characteristics have a minor influence. High screw density constructs have a lower risk for screw loosening. Level of evidence: 3 3-Retrospective register study.

We report on a laser producing bursts of GHz picosecond pulses with pulse repetition rate between 1 and 7.5 GHz, tens to thousands pulses per burst, 1 kW average power and inJ energy per burst. © 2024 The Author(s).

We demonstrate a 16 GHz repetition rate fiber-based optical parametric oscillator, pumped by an electro-optical comb tunable around 1.03 µm, delivering picosecond and wavelength tunable signal and idler pulses. Build-up and relaxation dynamics of these pulses are reported.

The Sahara and the Sahel are currently experiencing an increase in rainfall during the rainy season, possibly related to the strengthening of the hydrological cycle induced by global warming. However, the slowdown of the Atlantic Meridional Overturning Circulation (AMOC) might be able to counteract this trend, decreasing the North African monsoon rainfall in a timely, but highly uncertain, manner. During the early and mid-Holocene, the Sahara and the Sahel experienced a wet phase that offers a good analogue for testing the impact of an AMOC perturbation on the climate of this area. Here, we document this wet phase based on the sediment record of Lake Yoa from the central Sahara spanning the last 10,800 years at annual to decadal resolution. This record shows abrupt droughts at 8.2 kyr BP and at 6.3 kyr BP, which interrupted the humid period for a few decades. By modelling precipitation changes in the Lake Yoa area over the Holocene, we support the idea that these droughts were triggered by a slowdown of the AMOC. These results suggest that ongoing AMOC changes could severely weaken the African monsoon on decadal time scales. This process will reduce or even counteract the observed precipitation increase in these areas, highlighting the crucial need for reducing uncertainty in the rapidity of future AMOC weakening.

Using recycled concrete aggregates (RCA) in concrete has emerged as a promising solution to produce concrete with reduced environmental impact and adequate performance. However, a deeper understanding of the thermal and mechanical behavior of concrete made with RCA is still needed for further application in real structures. The present paper addresses one of the crucial issues for structural concrete: its behavior after exposure to high temperature. Four concrete mixes are studied: a reference concrete made with natural aggregates (NA), two concretes including 40% and 100% of coarse RCA as a direct replacement (DR) for coarse NA, and a concrete made with 100% of coarse RCA relying on a strength‐based replacement (SBR). The SBR concrete mix was designed to achieve the same performance (28 days compressive strength and slump) as the reference concrete. All specimens were exposed to temperatures of 200, 400, and 600°C. After cooling, samples were evaluated for residual mass loss, thermal, and mechanical properties. Microstructural quantitative analyses were conducted over several square millimeters to show that interfaces between the old and new cement pastes, peculiar to concrete made with RCA, do not further promote fracture development. The results show that after exposure to high temperatures, the thermal and mechanical performances of concrete made with RCA are reduced in the same manner and extent as in concrete made with NA. When the RCA‐based concrete is designed to achieve similar performance as concrete with NA at room temperature (SBR), the residual thermomechanical behavior is similar between both concretes.