We performed a complete set of laboratory experiments on a rock salt specimen to study the complex evolution of gas permeability under different loading conditions. The porosity of the studied rock ...salt is very low (~ 1%) and the initial permeability varies over 4.5 orders of magnitude. The Klinkenberg effect is only observed for the less permeable and damaged samples. The poroelastic coupling is almost negligible in our samples. Deviatoric loading under low confining pressure (1 MPa) induces a moderate increase in gas permeability from the dilatancy threshold due to microcracking. Measurement of ultrasonic wave velocities during uniaxial compression test showed an almost irreversible closure of pre-existing micro-cracks and the opening of axial micro-cracks that are perpendicular and parallel, respectively, to the uniaxial stress direction and allowed a precise determination of the dilatancy threshold. Under higher confining pressure (5 MPa), no increase in permeability was measured because the material becomes fully plastic which practically eliminates microcracking and thus dilatancy. Under hydrostatic loading, gas permeability decreases because of cracks closure and this decrease is irreversible due to the time-dependent self-healing process. Permeability increases slightly during dynamic mechanical and thermal fatigue due to microcracking, while it reduces during static fatigue (creep) thanks to the self-recovery process. All these results give strong confidence in the underground hydrogen storage in salt caverns which remains by far the safest solution because the different mechanisms (viscoplasticity with strain hardening, microcracking and cracks healing) involved in material deformation act in a competitive way to annihilate any significant permeability evolution.
A 3D fully coupled hydromechanical model for the simulation of fluid-driven fracture propagation through poroelastic saturated media is presented and compared to several analytical or numerical ...benchmarks. The hydromechanical coupling in the porous matrix is derived within the framework of the generalized Biot theory and the fluid flow in the fractures satisfies the lubrication equation. The presence and propagation of fluid-driven fractures is handled with the extended finite element method and the propagation of the fluid-driven fractures is governed by a mixed linear cohesive law relying on a stable mortar formalism. A comparison between numerical results and a semi-analytical solution for plane fluid-driven fractures in porous media assess the validity of the proposed model. Then, a procedure for the propagation of fluid-driven fractures on non predefined paths is detailed. In particular, the fracture reorientation angle is computed exclusively from cohesive quantities. Various numerical experiments are performed to study the interferences between neighboring fluid-driven fractures as well as the reorientation of fluid-driven fractures under complex stress conditions. Finally, the model is extended to discontinuity junctions and an application to arrays of vertical fractures initiated from horizontal wells is presented.
Contamination of groundwater resources by an immiscible organic phase commonly called NAPL (Non Aqueous Phase Liquid) represents a major scientific challenge considering the residence time of such a ...pollutant. This contamination leads to the formation of NAPL blobs trapped in the soil and impact of this residual saturation cannot be ignored for correct predictions of the contaminant fate. In this paper, we present results of micromodel experiments on the dissolution of pure hydrocarbon phase (toluene). They were conducted for two values of the Péclet number. These experiments provide data for comparison and validation of a two-phase non-equilibrium theoretical model developed by Quintard and Whitaker (1994) using the volume averaging method. The model was directly upscaled from the averaged pore-scale mass balance equations. The effective properties of the macroscopic model were calculated over periodic unit cells designed from images of the experimental flow cell. Comparison of experimental and numerical results shows that the transport model predicts correctly - with no fitting parameters - the main mechanisms of NAPL mass transfer. The study highlights the crucial need of having a fair recovery of pore-scale characteristic lengths to predict the mass transfer coefficient with accuracy.
Epithelioid Trophoblastic Tumor (ETT) is an extremely rare form of Gestational Trophoblastic Neoplasia (GTN). Knowledge on prognostic factors and optimal management is limited. We identified ...prognostic factors, optimal treatment, and outcome from the world's largest case series of patients with ETT.
Patients were selected from the international Placental Site Trophoblastic Tumor (PSTT) and ETT database. Fifty-four patients diagnosed with ETT or mixed PSTT/ETT between 2001 and 2016 were included. Cox regression analysis was used to identify prognostic factors for overall survival (OS).
Forty-five patients with ETT and 9 patients with PSTT/ETT were included. Thirty-six patients had FIGO stage I and 18 had stages II–IV disease. Patients were treated with surgery (n = 23), chemotherapy (n = 6), or a combination of surgery and chemotherapy (n = 25). In total, 39 patients survived, including 22 patients with complete sustained hCG remission for at least 1 year. Patients treated with surgery as first line treatment had early-stage disease and all survived. Most patients treated with chemotherapy with or without surgery had FIGO stages II–IV disease (55%). They underwent multiple lines of chemotherapy. Eleven of them did not survive. Interval since antecedent pregnancy and FIGO stage were prognostic factors of OS (p = 0.012; p = 0.023 respectively).
Advanced-stage disease and an interval of ≥48 months since the antecedent pregnancy are poor prognostic factors of ETT. Surgery seems adequate for early-stage disease with a shorter interval. Advanced-stage disease requires a combination of treatment modalities. Because of its rarity, ETT should be treated in a centre with experience in GTN.
•Epithelioid Trophoblastic Tumor (ETT) is an extremely rare potentially high-risk Gestational Trophoblastic Neoplasia.•ETT patients with advanced-stage disease or an interval of ≥48 months since antecedent pregnancy have poor outcome.•A surgical approach is recommended for ETT patients with early-stage disease.•Surgery and multi-chemotherapy is the preferred treatment modality for ETT patients with metastatic disease.•ETT patients should be treated in a trophoblastic disease center for optimal management.
Background
Epithelial ovarian carcinoma is the main cause of death from gynaecological cancers in the western world. The initial response rate to the frontline therapy is high. However, the prognosis ...of persistent and recurrent disease remains poor. During the two past decades, a new therapeutic approach to peritoneal carcinomatosis has been developed, combining maximal cytoreductive effort with hyperthermic intraperitoneal chemotherapy (HIPEC).
Methods
A retrospective, multicentric study of 246 patients with recurrent or persistent ovarian cancer, treated by cytoreductive surgery and HIPEC in two French centers between 1991 and 2008, was performed.
Results
An optimal cytoreductive surgery was possible in 92.2 % of patients. Mortality and morbidity rates were 0.37 % and 11.6 %, respectively. The overall median survival was 48.9 months. There was no significant difference in overall survival in patients with persistent or recurrent disease. In multivariate analysis, performance status was a significant prognostic factor in patients with extensive peritoneal carcinomatosis (peritoneal cancer index >10).
Conclusions
Salvage therapy combining optimal cytoreductive surgery and HIPEC is feasible and may achieve long-term survival in highly selected patients with recurrent ovarian carcinoma, including those with platinum resistant disease, with acceptable morbidity.
Objectives
To describe MRI features of accessory cavitated uterine mass (ACUM) with surgical correlations.
Methods
Eleven young women with an ACUM at pathology underwent preoperative pelvic MRI. Two ...experienced radiologists retrospectively analysed MR images in consensus to determine the lesion location within the uterus, its size, morphology (shape and boundaries), and structure reporting the signal and enhancement of its different parts compared to myometrium. The presence of an associated urogenital malformation or other gynaecological anomaly was reported. MRI features were correlated with surgical findings.
Results
All 11 lesions were well correlated with surgical findings, lateralised (seven were left-sided), and located under the horn and the round ligament insertion. Nine were located within the external myometrium, bulging into the broad ligament. Two were extrauterine, entirely located within the broad ligament. On MRI, the mean size was 28 mm (range 17–60 mm). Nine lesions were round-shaped, two were oval; all had regular boundaries. At surgery, the ACUM were not encapsulated but were possible to enucleate. On MRI, all lesions were well defined and showed a central haemorrhagic cavity surrounded by a regular ring (mean thickness, 5 mm) which had the same signal compared to the junctional zone. ACUM was isolated in all women, without urogenital malformation, adenomyosis or deep endometriosis.
Conclusions
On MRI, ACUM was an isolated round accessory cavitated functional non-communicating horn-like aspect in an otherwise normal uterus. MRI may facilitate timely diagnosis and appropriate curative fertility-sparing laparoscopic resection.
Key Points
• ACUM is rare, with delayed diagnosis in young women with severe dysmenorrhoea. Pelvic MRI facilitates timely diagnosis and appropriate curative fertility-sparing laparoscopic resection.
• Quasi-systematically located under the uterine round ligament insertion, ACUM may be intramyometrial and/or in the broad ligament.
• On MRI ACUM resemble a non-communicating functional accessory horn within a normal uterus; the mass, most often round-shaped, had a central haemorrhagic cavity surrounded by a regular ring which had the same low signal compared to the uterine junctional zone.
Introduction and hypothesis
We assessed 3-year anatomic and functional results using synthetic glue to fix mesh in laparoscopic sacrocolpopexy.
Methods
Prospective multicenter cohort study in three ...academic urogynecology departments. Seventy consecutive patients with stage ≥ 3 POP-Q (Pelvic Organ Prolapse Quantification) anterior and/or apical prolapse underwent laparoscopic sacrocolpopexy using synthetic surgical glue to fix anterior and posterior meshes to the vagina. Patients were followed up at 1, 2 and 3 years. Primary outcome was anterior and apical anatomic success (POP-Q stage ≤ 1) at 3 years. Secondary outcomes comprised functional results (international quality of life and sexuality scales), mesh-related morbidity and urinary incontinence at 3 years.
Results
Mean age was 56.7 ± 1.2 years. Mean follow-up was 43 months. Anterior compartment anatomic success rate was 87% at 2 years (Ba, −2.4 cm;
p
< 0.0001) and 86.5% at 3 years (Ba, −2.3 cm;
p
< 0.0001); apical success was 96.3% at 2 years (C, −6.8 cm;
p
< 0.0001) and 97.3% at 3 years (C, −6.5 cm;
p
< 0.0001). All quality-of-life scores improved significantly and lastingly at 3 years: PFDI-20, PFIQ-7 and PISQ-12, respectively,
p
< 0.0001,
p
< 0.0001 and
p
= 0.01. There was one case of vaginal mesh exposure at 3 years (2.8%) and five of mesh shrinkage at 1 year (7.8%), none at 2 years and two at 3 years (5.4%). Urinary incontinence rate was 29.7% at 1 year, 14.8% at 2 years and 11.1% at 3 years.
Conclusion
Vaginal mesh adhesive in laparoscopic sacrocolpopexy remained effective at 3 years, with excellent tolerance and no specific complications. Anatomic and functional results were good and enduring in terms of both anterior and apical correction.
This work was carried out in order to quantify the impact of the pyrolysis heating rate both on the properties of the residual charcoal and on the behaviour during gasification by H
2O of the ...charcoal. The experiments were conducted on 10
mm diameter beech wood spheres, pyrolysed at atmospheric pressure under heating rates covering the range from very slow, 2.6
K
min
−1, to very rapid, over 900
K
min
−1, i.e. the highest value that can be reached. When charcoal is submitted to gasification at 20% H
2O in N
2 at 1200
K, the ratio of the times for complete conversion reach 2.6. Such a difference is considerable as far as an industrial application is concerned. The initial properties of the charcoal such as apparent density, porosity, and pore surface area obtained by N
2 or Ar adsorption were measured in order to explain the differences in gasification kinetics within the charcoal. The charcoal particles exhibit densities as different as 219–511
kg
m
−3 and porosities between 87 and 70% for charcoal prepared at 900 and 2.6
K
min
−1 respectively. The specific surface area is higher than 600
m
2
g
−1 for three charcoals. Influence of ash content of the initial charcoals, at 1.6–2.7%, is also regarded with particular attention to explain the observed differences in gasification kinetics.
In this paper, the macroscopic representation of one-phase incompressible flow in fractured and cavity (or vuggy) porous media is studied from theoretical and numerical points of view. A ...single-domain (or equivalently a Darcy-Brinkman) type of approach is followed to describe the momentum transport at Darcy scale where the fracture or cavity region and porous matrix region are well identified. The Darcy scale model is upscaled yielding a macroscopic momentum equation operating on the equivalent homogeneous medium. Numerical solution to the associated closure problem is proposed in order to compute the effective permeability. Numerical results on some model fractured and cavity media are discussed and compared to some analytical results.
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