Treatment options for Hepatitis C infection have greatly improved with direct-acting antiviral (DAA) combinations achieving high cure rates. Nevertheless, the cost of this treatment is still high and access to treatment in many countries has been preferentially reserved for patients with more severe fibrosis (F3 and F4). In this French nationwide study, we investigated the epidemiological characteristics and genotype distribution of hepatitis C virus (HCV) in treatment-naive patients with METAVIR fibrosis stages between F0 and F2 in order to identify patient profiles that became eligible for unrestricted treatment in a second period. Between 2015 and 2016 we collected data from nine French university hospitals on a total of 584 HCV positive patients with absent, mild or moderate liver fibrosis. The most represented genotypes were genotype 1b (159/584; 27.2%), followed by genotype 1a (150/584; 25.7%); genotype 3 (87/584: 14.9%); genotype 4 (80/584; 13.7%). Among genotype 4: 4a was predominantly encountered with 22 patients (27.5% of genotype 4). Genotypes 1b and 1a are currently the most frequent virus types present in treatment-naive patients with mild fibrosis in France. They can be readily cured using the available DAA. Nevertheless, non-a/non-d genotype 4 is also frequent in this population and clinical data on the efficacy of DAA on these subtypes is missing. The GEMHEP is the French group for study and evaluation of viral hepatitis on a national scale. Data collection on epidemiological and molecular aspects of viral hepatitis is performed on a regular basis in all main French teaching hospitals and serves as a basis for surveillance of these infections. Analysis and trends are regularly published on behalf of the GEMHEP group. Data collection was performed retrospectively over the 2015–2016 period, covering nine main university hospitals in France. A total of 584 hepatitis C positive patients were included in this study. Genotyping of the circulating viruses showed a high prevalence of genotypes 1b and 1a in our population. The epidemiology of hepatitis C is slowly changing in France, particularly as a consequence of the rise of ‘non-a non-d’ genotype 4 viruses mainly originating from African populations. More data concerning treatment efficacy of these genotypes is needed in order to guide clinical care.

Thermodynamic fluctuations of pressure, density, temperature or entropy $\{p^{\prime },\unicode[STIX]{x1D70C}^{\prime },T^{\prime },s^{\prime }\}$ in compressible aerodynamic turbulence, although generated by the flow, are fundamentally related to one another by the thermodynamic equation of state. Ratios between non-dimensional root-mean-square (r.m.s.) levels ($\text{CV}_{p^{\prime }}:=\bar{p}^{-1}\,p_{rms}^{\prime }$, $\text{CV}_{\unicode[STIX]{x1D70C}^{\prime }}:=\bar{\unicode[STIX]{x1D70C}}^{-1}\,\unicode[STIX]{x1D70C}_{rms}^{\prime }$, $\text{CV}_{T^{\prime }}:=\bar{T}^{-1}\,T_{rms}^{\prime }$), along with all possible 2-moment correlation coefficients $\{c_{\unicode[STIX]{x1D70C}^{\prime }T^{\prime }},c_{p^{\prime }\unicode[STIX]{x1D70C}^{\prime }},c_{p^{\prime }T^{\prime }},c_{s^{\prime }\unicode[STIX]{x1D70C}^{\prime }},c_{s^{\prime }T^{\prime }},c_{s^{\prime }p^{\prime }}\}$, represent, in the sense of Bradshaw (Annu. Rev. Fluid Mech., vol. 9, 1977, pp. 33–54), the thermodynamic turbulence structure of the flow. We use direct numerical simulation (DNS) data, both for plane channel flow and for sustained homogeneous isotropic turbulence, to determine the range of validity of the leading-order, formally $O(\text{CV}_{\unicode[STIX]{x1D70C}^{\prime }})$, approximations of the exact relations between thermodynamic turbulence structure parameters. Available DNS data are mapped on the $(\text{CV}_{\unicode[STIX]{x1D70C}^{\prime }}^{-1}\,\text{CV}_{T^{\prime }},c_{\unicode[STIX]{x1D70C}^{\prime }T^{\prime }})$-plane and their loci, identified using the leading-order approximations, highlight specific behaviour for different flows or flow regions. For the particular case of sustained compressible homogeneous isotropic turbulence, it is shown that the DNS data collapse onto a single curve corresponding to $c_{s^{\prime }T^{\prime }}\approxeq 0.2$ (for air flow), while the approximation $c_{s^{\prime }p^{\prime }}\approxeq 0$ fits reasonably well wall turbulence DNS data, providing building blocks towards the construction of simple phenomenological models.

The paper investigates the dissipation tensor $\unicode[STIX]{x1D700}_{ij}$ in wall turbulence. Available direct numerical simulation (DNS) data are examined to illustrate the differences in the anisotropy of the dissipation tensor $\unicode[STIX]{x1D700}_{ij}$ with respect to the anisotropy of the Reynolds stresses $\unicode[STIX]{x1D633}_{ij}$. The budgets of the transport equations of the dissipation tensor $\unicode[STIX]{x1D700}_{ij}$ are studied using novel DNS data of low Reynolds number turbulent plane channel flow with spatial resolution sufficiently fine to accurately determine the correlations of products of two-derivatives of fluctuating velocities $u_{i}^{\prime }$ and pressure $p^{\prime }$ which appear in various terms. Finally, the influence of the Reynolds number on the diagonal components of $\unicode[STIX]{x1D700}_{ij}$ ($\unicode[STIX]{x1D700}_{xx}$, $\unicode[STIX]{x1D700}_{yy}$, $\unicode[STIX]{x1D700}_{zz}$) and on the various terms in their transport equations is studied using available DNS data of Vreman and Kuerten (Phys. Fluids, vol. 26, 2014b, 085103).

We investigate the fluctuations of thermodynamic state variables in compressible aerodynamic wall turbulence, using results of direct numerical simulation (DNS) of compressible turbulent plane channel flow. The basic transport equations governing the behaviour of thermodynamic variables (density, pressure, temperature and entropy) are reviewed and used to derive the exact transport equations for the variances and fluxes (transport by the fluctuating velocity field) of the thermodynamic fluctuations. The scaling with Reynolds and Mach number of compressible turbulent plane channel flow is discussed. Statistics and correlation coefficients of the thermodynamic fluctuations are examined. Finally, detailed budgets of the transport equations for the variances and fluxes of the thermodynamic variables are analysed. The implications of these results, leading both to the understanding of the thermodynamic interactions in compressible wall turbulence and to possible improvements in statistical modelling, are assessed. Finally, the required extension of existing DNS data to fully characterise this canonical flow is discussed.

The purpose of the present paper is to study the influence of wall echo on pressure fluctuations ${p}^{\prime } $, and on statistical correlations containing ${p}^{\prime } $, namely, redistribution ${\phi }_{ij} $, pressure diffusion ${ d}_{ij}^{(p)} $ and velocity pressure-gradient ${\Pi }_{ij} $. We extend the usual analysis of turbulent correlations containing pressure fluctuations in wall-bounded direct numerical simulations (Kim, J. Fluid Mech., vol. 205, 1989, pp. 421–451), separating ${p}^{\prime } $ not only into rapid ${ p}_{(r)}^{\prime } $ and slow ${ p}_{(s)}^{\prime } $ parts (Chou, Q. Appl. Maths, vol. 3, 1945, pp. 38–54), but also further into volume (${ p}_{(r; \mathfrak{V})}^{\prime } $ and ${ p}_{(s; \mathfrak{V})}^{\prime } $) and surface (wall echo, ${ p}_{(r; w)}^{\prime } $ and ${ p}_{(s; w)}^{\prime } $) terms. An algorithm, based on a Green’s function approach, is developed to compute the above splittings for various correlations containing pressure fluctuations (redistribution, pressure diffusion, velocity pressure-gradient), in fully developed turbulent plane channel flow. This exact analysis confirms previous results based on a method-of-images approximation (Manceau, Wang & Laurence, J. Fluid Mech., vol. 438, 2001, pp. 307–338) showing that, at the wall, ${ p}_{(\mathfrak{V})}^{\prime } $ and ${ p}_{(w)}^{\prime } $ are usually of the same sign and approximately equal. The above results are then used to study the contribution of each mechanism to the pressure correlations in low-Reynolds-number plane channel flow, and to discuss standard second-moment-closure modelling practices.

This work is dedicated to the resolution of a singular equation set in the half-space, with a diffusion coefficient that blows up on the boundary. More precisely, for a datum g: ℝ+3 → ℝ, our problem involves seeking u: ℝ+3 → ℝ as a formal solution to

We give existence and uniqueness results of weak and strong solutions in suitable weighted spaces, where the weight depends on x3.

In this paper we are interested in a mathematical model of migration of grass eels in an estuary. We first revisit a previous model proposed by O. Arino and based on a degenerate convection-diffusion equation of parabolic-hyperbolic type with time-varying subdomains. Then, we propose an adapted mathematical framework for this model, we prove a result of existence of a weak solution and we propose some numerical simulations.

Summary

Background and objective: Because gastric mucosal PCO2 must be referenced to arterial values via a gastric-to-arterial PCO2 gap (Pg–aCO2), the gastric-to-end-tidal PCO2 difference (Pg–etCO2) may be proposed as a surrogate method to monitor Pg–aCO2. However, the influence of arterial-to-end-tidal PCO2 (Pa–etCO2) on its value remains unknown. Pa–etCO2 may be enhanced by a low cardiac output and subsequent reduced perfusion of the lungs. This study was designed to compare such gaps observed during abdominal surgery in patients with or without preoperative cardiac dysfunction.

Methods: Haemodynamic, metabolic and tonometric variables were measured in seven patients with Crohn's disease and in five patients with chronic heart failure scheduled for abdominal surgery. Data were collected before skin incision (T0); at extractor placement (T1), 30 (T2) and 60 (T3) min later; at organ extraction (T4), 30 (T5) and 60 (T6) min later, and at the end of surgery (T7).

Results: Gradients appeared larger in the cardiac group. The difference was significant for Pg–etCO2 during the whole study period, while it was only reached at T1–T2 for Pa–etCO2 and at T5–T6 for Pg–aCO2. Gaps did not change significantly over the peroperative time points in either group. No major haemodynamic variations were registered in either group.

Conclusions: In patients with preoperative chronic heart failure, Pg–etCO2 remained constant throughout a major general surgical procedure and was only moderately influenced by the Pa–etCO2 gap. In these patients, Pg–etCO2 may be used as a reliable index of gastrointestinal perfusion after control of PaCO2.

Background and objective Ischaemic colitis can be a serious complication after aortic surgery. The paucity of clinical symptoms makes its diagnosis particularly difficult and often delayed. Automated on-line tonometry is now proposed to monitor intestinal perfusion. This study was designed to assess the use of semi-continuous sigmoid-to-arterial [P(r-a)CO2] PCO2 gap monitoring in aortic surgery to detect colonic ischaemia.

Methods This prospective clinical study was realized at the University Hospital of Lille, France, including eight males scheduled for abdominal aortic aneurysm surgery. Intraoperative and postoperative P(r-a)CO2 values were compared with conventional monitoring and colonic mucosa aspect performed by sigmoidoscopy 48 h after surgery. Haemodynamic variables, O2 delivery (DO2), O2 consumption (VO2), O2 extraction (ERO2), lactate, P(v-a)CO2, P(r-a)CO2 were measured peroperatively and every 4 h during a 48-h postoperative period.

Results Intraoperative P(r-a)CO2 values increased significantly with the highest value (4.36 ± 3.42 kPa) observed during aortic clamping when DO2 was the most altered. P(r-a)CO2 continued to deteriorate after surgery with the maximal values between 8 (4.79 ± 3.85 kPa) and 12 (4.68 ± 3.26 kPa) h after surgery. This peak was associated with a significant ERO2 increase counterbalancing an increase of VO2 whereas DO2 tended to decrease. P(r-a)CO2 values began to decrease only at the end of the study. The highest values of P(r-a)CO2 were registered in patients with the most altered haemodynamic variables, severe ischaemic colitis along with higher hospital lengths of stay.

Conclusion Taken together, these data suggest that regional and automated capnometry may be easily used non-invasively to detect peroperative intestinal ischaemia in aortic surgery.

Chemical solution epitaxy was used to deposit an epitaxial film of Gd2O3 on roll-textured nickel. A 2-methoxyethanol solution of gadolinium methoxyethoxide was used for spin-coating and dip-coating. Films were crystallized using a heat treatment at 1160 °C for 1 h in 4% H2/96% Ar. Single-layer films were approximately 600 Å in thickness, and thicker films could be produced using multiple coatings. θ/2θ x-ray diffractograms revealed only (0041) reflections, indicating a high degree of out-of-plane texture. A pole-figure about the Gd2O3 (222) reflection indicated a single in-plane epitaxy. Scanning electron microscopy showed that the films were smooth, continuous, and free of pin holes. Atomic force microscopy revealed an average surface roughness of 53 Å. Electron diffraction indicated that the misalignment of the majority of the grains in the plane was less than 10°. High-current (0.4 MA/cm2) Yba2Cu3O7–δ films were grown on roll-textured nickel substrates using Gd2O3 as the base layer in a three-layer buffer structure.

Using solution chemistry, epitaxial films of rare-earth oxides of the general formula RE2O3 (where RE = Sm to Lu) were prepared on cubic-textured nickel tapes. Solutions of metal methoxyethoxides or metal acetate/methoxyethoxides in 2-methoxyethanol were used to coat rolltextured nickel tapes using either spin-coating or dip-coating. Coated tapes were subsequently heated in a reducing atmosphere at temperatures between 950 °C and 1160 °C for varying lengths of time. Film quality was determined using X-ray diffraction and electron and surface probe microscopy. Films were found to be oriented both in and out-of-plane of the substrate, free of pinholes and gross defects, and of sufficient quality for use as substrates for high Tc, superconductors.

A gene encoding a protein of 646 amino acid residues with a molecular mass of 71·3 kDa showing homology to the cytoplasmic form of the 70 kDa heat shock protein was cloned and sequenced from the nematode parasite Trichinella britovi (Tb). The gene was expressed in vitro as a protein of 71 kDa that was immunoprecipitated by a Trichinella-infected rabbit serum. Monospecific polyclonal antibodies raised against the recombinant Tb Hsp70 expressed in Escherichia coli, recognized a protein of 70 kDa by Western blot analysis of Tb soluble antigen (muscular stage). Tb Hsp70 was located in the nuclei of the muscle larvae as determined by the indirect immunofluorescent pattern on cross-sections of the worm. The expression of this protein was not detected in adult worm nuclei suggesting a differential expression of Hsp70 between the 2 stages of Trichinella.

We try to explain the large differences observed in the proportion of needles colonized by fungal species in coniferous litter by spore dispersal properties. We constructed a population dynamics model, assuming that litter is a resource that is fragmented into ephemeral units, periodically produced. Spore dispersion on needles on a small spatial scale was assumed to follow a Poisson distribution. The model was compared with an experimental system using Thysanophora penicillioides on Abies alba needles and its relevance to field conditions is discussed.

SnO2–CuO mixture phase has been prepared by pyrolysis of an aerosol produced by ultrahigh frequency of different precursor solutions. As-received samples were annealed in different conditions to study the influence of the temperature on the microstructure. Scanning electron microscopy showed that the samples consisted of hollow spherical particles and rings, depending on the precursor solution utilized. The evolution of conductance under both pure and polluted air is discussed.

The dielectric properties of the heat-resistant heterocyclic polymers are governed by their chemical structure and the absence of unwanted dipoles. A polyphenylquinoxaline is taken as an example of the effect of the dipole symmetry. In the particular case of polyimides, it is obvious that the dehydrocyclization of the intermediate polyamic acid has to be completed to produce the lowest achievable permittivity. This is illustrated by the polycondensation in solution of the polyimides based on 4,4'-(9H-fluoren-9-ylidene)-bisbenzeneamine. In addition, the spatial conformation of the macromolecular chain can also play an important role. The chemistry of a polyimide prepared from 4,4'-(1,3-benzenedicarbonyl) bis(1,2-benzenedicarboxylic acid dianhydride) allows to discuss this topic. However, a dielectric constant of 2.7 seems to be the ultimate value achievable for dense films prepared with the most performing polymers. The introduction of homogeneously distributed micro-voids allows the preparation of dielectric films with a permittivity lower than 2.0. The modification of a polymer with tertiobutyl carbonate (t.BOC) groups is a promising approach because it offers a large processability window.