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Underground Hydrogen Storage (UHS) is an emerging large-scale energy storage technology. Researchers are investigating its feasibility and performance, including its injectivity, productivity, and storage capacity through numerical simulations. However, several ad-hoc relative permeability and capillary pressure functions have been used in the literature, with no direct link to the underlying physics of the hydrogen storage and production process. Recent relative permeability measurements for the hydrogen-brine system show very low hydrogen relative permeability and strong liquid phase hysteresis, very different to what has been observed for other fluid systems for the same rock type. This raises the concern as to what extend the existing studies in the literature are able to reliably quantify the feasibility of the potential storage projects. In this study, we investigate how experimentally measured hydrogen-brine relative permeability hysteresis affects the performance of UHS projects through numerical reservoir simulations. Relative permeability data measured during a hydrogen-water core-flooding experiment within ADMIRE project is used to design a relative permeability hysteresis model. Next, numerical simulation for a UHS project in a generic braided-fluvial water-gas reservoir is performed using this hysteresis model. A performance assessment is carried out for several UHS scenarios with different drainage relative permeability curves, hysteresis model coefficients, and injection/production rates. Our results show that both gas and liquid relative permeability hysteresis play an important role in UHS irrespective of injection/production rate. Ignoring gas hysteresis may cause up to 338% of uncertainty on cumulative hydrogen production, as it has negative effects on injectivity and productivity due to the resulting limited variation range of gas saturation and pressure during cyclic operations. In contrast, hysteresis in the liquid phase relative permeability resolves this issue to some extent by improving the displacement of the liquid phase. Finally, implementing relative permeability curves from other fluid systems during UHS performance assessment will cause uncertainty in terms of gas saturation and up to 141% underestimation on cumulative hydrogen production. These observations illustrate the importance of using relative permeability curves characteristic of hydrogen-brine system for assessing the UHS performances. • Experimentally measured hydrogen-brine relative permeability curves show distinct characteristics compared to that of other fluid systems. • UHS performances under different relative permeability curves are compared. • Relative permeability curves from other fluid systems are not suitable to act as proxy to hydrogen-brine system in reservoir-scale UHS simulation. [ABSTRACT FROM AUTHOR]

• Residual trapping ability decreases with porosity and increases with heterogeneity. • Variance in the drainage saturation field best predicts residual gas trapping. • Correlation length and lamination direction have no effect on residual trapping. • Mesoscale trapping mechanism can be as important as pore-scale trapping mechanism. • Voxel-level residual trapping amount is correlated with permeability not porosity. To increase confidence in the long-term security of CO 2 geologic storage, reliable predictions of the level of post-injection CO 2 residual trapping are needed. In this study, we conduct CO 2 /water coreflooding experiments at reservoir conditions on nine core samples with different degrees and types of heterogeneity to find the best petrophysical properties for predicting sandstone CO 2 residual trapping ability. We are able to extract petrophysical properties such as porosity, permeability, degree of mesoscale heterogeneity, and spatial correlation lengths of petrophysical property fields in different directions using a CT scanner. Experimental results show that CO 2 residual trapping ability decreases with porosity and increases with the degree of heterogeneity. A number of metrics for heterogeneity are evaluated, including the Dykstra-Parsons coefficient and the variance in voxel-level CO 2 drainage saturation fields as well as the porosity and permeability fields. The variance of the saturation distribution during drainage provides the best predictor of residual gas trapping. By extrapolating the relationship between the degree of heterogeneity and the linear trapping coefficient, we show that pore-scale trapping mechanisms account for 46–97% of the residually trapped CO 2 and the mesoscale capillary heterogeneity trapping mechanism accounts for 3–54% of the residually trapped CO 2 for the nine sandstone samples tested. [ABSTRACT FROM AUTHOR]

Recent studies have demonstrated the importance of transverse dispersion for dilution and mixing of solutes but most observations have remained limited to two-dimensional sand-box models. We present a new core-flood test to characterize solute transport in 3-D natural-rock media. A device consisting of three annular regions was used for fluid injection into a cylindrical rock core. Pure water was injected into the center and outer region and a NaI solution into the middle region. Steady state transverse dispersion of NaI was visualized with an X-ray medical CT-scanner for a range of Peclét numbers. Three methods were used to calculate D t : (1) fitting an analytical solution, (2) analyzing the second-central moment, and (3) analyzing the dilution index and reactor ratio. Transverse dispersion decreased with distance due to flow focusing. Furthermore, D t in the power-law regime showed sub-linear behavior. Overall, the reactor ratios were high confirming the homogeneity of Berea sandstone. [ABSTRACT FROM AUTHOR]

Mutations in SCN8A are associated with epilepsy and intellectual disability. SCN8A encodes for sodium channel Nav1.6, which is located in the brain. Gain-of-function missense mutations in SCN8A are thought to lead to increased firing of excitatory neurons containing Nav1.6, and therefore to lead to increased seizure susceptibility. We hypothesized that sodium channel blockers could have a beneficial effect in patients with SCN8A-related epilepsy by blocking the overactive Nav1.6 and thereby counteracting the effect of the mutation. Herein, we describe 4 patients with a missense SCN8A mutation and epilepsy who all show a remarkably good response on high doses of phenytoin and loss of seizure control when phenytoin medication was reduced, while side effects were relatively mild. In 2 patients, repeated withdrawal of phenytoin led to the reoccurrence of seizures. Based on the findings in these patients and the underlying molecular mechanism we consider treatment with (high-dose) phenytoin as a possible treatment option in patients with difficult-to-control seizures due to an SCN8A mutation. [ABSTRACT FROM AUTHOR]

• Rate-dependent anisotropic saturation functions used to simulate CO 2 plume spreading. • Different plume shapes as compared to those modelled with conventional functions. • Nested geologic heterogeneity is a major control on plume migration. • Buoyancy force drives CO 2 to up-dip direction in inclined strata. • High injection rates enhance lateral spreading and low rates promote vertical migration. In this field-data-based simulation study, we apply novel rate-dependent, anisotropic saturation functions curve-fitted to match the flow behaviour of laminated sand- and siltstones from the CO2CRC's Otway International Test Centre (Australia), in well-spot simulations of plume spreading at the site. Scenario analysis is conducted by performing simulations on various stochastic model realisations under different conditions, investigating what controls plume migration. Results indicate that high-permeability streaks and intraformational baffles determine plume spreading in flat-lying stratigraphy. Displacement of CO 2 is unstable and focussed by high-permeability streaks, leading to multi-layer plumes. In inclined stratigraphy, buoyancy forces control plume migration channelling it up dip. However, high-permeability streaks still influence plume shape. Comparisons for different injection rates show that heterogeneity-induced fingering dominates at high injection rates, whereas gravity override and vertical movement of the plume are prominent at low injection rates. Continuous build-up of fluid pressure in the storage horizon influences the properties of CO 2 when no-flow (closed) lateral boundary conditions are applied. By contrast, a marked pressure drop occurs in the near-well region for hydrostatic (open) lateral boundary conditions. These also foster uneven heterogeneity-fingering of the plume. Since flow velocity in the highly heterogeneous Paaratte formation varies over many orders of magnitude, force balances range between the capillary and the viscous limit even at some distance to the injector. A comparison with simulations based on standard Brooks-Corey saturation functions shows that taking flow-rate dependence and anisotropy into account leads to significant differences in the shape of the evolving CO 2 plume and the saturation within. [ABSTRACT FROM AUTHOR]

Characterizing the wettability of hydrogen (H 2)–methane (CH 4) mixtures in subsurface reservoirs is the first step towards understanding containment and transport properties for underground hydrogen storage (UHS). In this study, we investigate the static contact angles of H 2 –CH 4 mixtures, in contact with brine and Bentheimer sandstone rock using a captive-bubble cell device at different pressures, temperatures and brine salinity values. It is found that, under the studied conditions, H 2 and CH 4 show comparable wettability behaviour with contact angles ranging between [25°–45°]; and consequently their mixtures behave similar to the pure gas systems, independent of composition, pressure, temperature and salinity. For the system at rest, the acting buoyancy and surface forces allow for theoretical sensitivity analysis for the captive-bubble cell approach to characterize the wettability. Moreover, it is theoretically validated that under similar Bond numbers and similar bubble sizes, the contact angles of H 2 and CH 4 bubbles and their mixtures are indeed comparable. Consequently, in large-scale subsurface storage systems where buoyancy and capillary are the main acting forces, H 2 , CH 4 and their mixtures will have similar wettability characteristics. [Display omitted] • Static contact angles for H 2 –CH 4 /brine/rock systems were directly measured. • All gas mixtures showed comparable behaviour and no P, T or salinity dependency was found. • A theoretical validation of the results is presented based on the Young Laplace Eq. • For similar N B O and bubble sizes, the contact angles for H 2 and CH 4 are comparable. [ABSTRACT FROM AUTHOR]

Abstract: Background: Fatigue is an important symptom in adult multiple sclerosis (MS) and it is likely to occur in children with MS. It is currently unknown whether children who experienced a monophasic inflammatory demyelinating event of the central nervous system in the past also suffer from fatigue. Methods: We studied the presence and severity of fatigue in 32 children (18 boys, 14 girls) between 11–17 years old (mean: 14 years, 10 months) with a monophasic inflammatory demyelinating disease (n =22) or definite MS (n =10). This was measured with the Checklist Individual Strength. A score of ≥40 on the severity of fatigue subscale indicated the presence of severe fatigue. We also examined the relation between fatigue and depression (assessed by the Child Depression Inventory). Additionally we measured the health-related quality of life (HRQoL), using the TNO-AZL Child Quality of Life child form. We compared the scores of the MS and monophasic patients with the scores of healthy Dutch children. Results: The highest scores on the fatigue scales subjective fatigue and physical activity were found in the children with MS. Only 1 of the monophasic patients suffered from severe fatigue in contrast to 4 of the MS patients. In the MS group fatigue and depression were correlated. MS patients experienced a lower HRQoL on the scales locomotor functioning, cognitive functioning and interaction with peers. Conclusion: The occurrence of fatigue is very rare after a monophasic inflammatory demyelinating event in the past. As expected, fatigue occurs more frequent in paediatric MS patients. [Copyright &y& Elsevier]

• A new macroscopic capillary number for horizontally layered systems is presented. • Effective flow-rate dependent saturation functions are derived analytically. • A model is presented to predict the impact of laminations on CO 2 plume migration. We investigate the impact of sub-grid scale horizontal lamination on the migration of the CO 2 plume during geologic sequestration. A new physics-based model that includes the effects of capillary and viscous forces is used to obtain effective flow-rate dependent capillary pressure and relative permeability functions. For this purpose a macroscopic capillary number is derived that accurately describes the viscous-capillary force balance. The model is based on the fractional flow approach and is implemented in an extended radial Buckley-Leverett solution. This provides an easy way to investigate the impact of mm to m scale laminae on the frontal advance of the plume. Our work shows that at injection rates and volumes commonly used at geologic sequestration sites, capillary number dependency is important during the initial phase of the injection period. At later stages, the use of a capillary limit solution will be a valid approximation, even close to the injection well. [ABSTRACT FROM AUTHOR]

Underground Hydrogen Storage (UHS) is an attractive technology for large-scale (TWh) renewable energy storage. To ensure the safety and efficiency of the UHS, it is crucial to quantify the H 2 interactions with the reservoir fluids and rocks across scales, including the micro scale. This paper reports the experimental measurements of advancing and receding contact angles for different channel widths for a H 2 /water system at P = 10 bar and T = 20 °C using a microfluidic chip. To analyse the characteristics of the H 2 flow in straight pore throats, the network is designed such that it holds several straight channels. More specifically, the width of the microchannels range between 50 μ m and 130 μ m. For the drainage experiments, H 2 is injected into a fully water saturated system, while for the imbibition tests, water is injected into a fully H 2 -saturated system. For both scenarios, high-resolution images are captured starting the introduction of the new phase into the system, allowing for fully-dynamic transport analyses. For better insights, N 2 /water and CO 2 /water flows were also analysed and compared with H 2 /water. Results indicate strong water-wet conditions with H 2 /water advancing and receding contact angles of, respectively, 13°–39°, and 6°–23°. It was found that the contact angles decrease with increasing channel widths. The receding contact angle measured in the 50 μ m channel agrees well with the results presented in the literature by conducting a core-flood test for a sandstone rock. Furthermore, the N 2 /water and CO 2 /water systems showed similar characteristics as the H 2 /water system. In addition to the important characterization of the dynamic wettability, the results are also crucially important for accurate construction of pore-scale simulators. [Display omitted] • Dynamic contact angles for H 2 /water/glass system were measured using a microchip. • H 2 dynamic contact angles decreased with increasing channel width. • H 2 advancing and receding contact angles were found, respectively, 13–39° and 6–23°. • Similar contact angles were found for H 2 , N 2 and gaseous CO 2. [ABSTRACT FROM AUTHOR]

It may be difficult for clinicians to estimate the prognosis of pediatric acute transverse myelitis (ATM). The aim of this study was to define prognostic factors for relapsing disease and poor outcome in pediatric ATM. This prospective cohort study included 49 children, 18 boys and 31 girls (median age 13.1 years, IQR 6.5–16.2) with a first episode of ATM. Factors associated with relapsing disease and poor outcome (Expanded Disability Status Scale (EDSS) ≥ 4) were assessed during a median follow-up of 37 months (IQR 18–75). In total, 14 patients (29%) experienced ≥ 1 relapse(s) and nine patients (18%) had a poor outcome. Factors at onset associated with relapsing disease included higher age (16.1 vs. 11.6 years, p = 0.002), longer time to maximum severity of symptoms (5.5 vs. 3 days, p = 0.01), lower maximum EDSS score (4.0 vs. 6.5, p = 0.003), short lesion on spinal MRI (64 vs. 21%, p = 0.006), abnormalities on brain MRI (93 vs. 44%, p = 0.002) and presence of oligoclonal bands in cerebrospinal fluid (67 vs. 14%, p = 0.004). The only factor associated with poor outcome was presence of a spinal cord lesion on MRI without cervical involvement (56 vs. 14%, p = 0.02). Pediatric ATM patients presenting with clinical, radiological and laboratory features associated with multiple sclerosis (MS) are at risk for relapsing disease. In absence of these known MS risk factors at onset of disease these patients are at low risk for relapses. Only a minority of pediatric ATM patients in this cohort have a poor outcome. [ABSTRACT FROM AUTHOR]

We sought to identify clinical and radiologic features predicting early relapse after a diagnosis of multiple sclerosis in children. In this nationwide retrospective multicenter study in The Netherlands, we included 28 children with multiple sclerosis with onset before age 16 years. Magnetic resonance images and clinical features at the onset of disease were evaluated. The mean follow-up time was 55 months. Twenty children (71%) had a relapse during follow-up. We found that the presence of at least three of four Barkhof magnetic resonance imaging criteria at the onset of multiple sclerosis signs is predictive of early relapse after a diagnosis of multiple sclerosis in children (P <0.05). [Copyright &y& Elsevier]

Abstract: Objective: To assess if hearing loss is a feature of Joubert syndrome (JBS), one of the ciliopathies and therefore possibly associated with hearing loss. Design: Retrospective case series. Setting: University Children''s Hospital. Patients: Dutch patients with JBS. Main outcome measures: Audiological data. Results: Data from 22 Dutch Joubert syndrome (JBS) cases (17 males, 5 females) aged 3–40 years were available. Audiological tests were successfully performed in 14 cases. Three cases (aged 17–26 years) showed very mild sensorineural hearing loss (SNHL) at different frequencies. Conductive hearing loss due to middle ear infections occurred frequently in young JBS children (6 out of 22 cases). In three cases (aged 3–13 years) the parents reported the child was hypersensitive to sound. Conclusion: We found no evidence for significant hearing loss in Joubert syndrome patients. However, given the compromised speech development in JBS, conductive hearing loss due to middle ear infections should be treated vigorously. SNHL at a later age cannot be excluded on the basis of our data, given the sample size. Three of the older cases showed discretely increased hearing thresholds. Analogous to the ciliopathy Bardet–Biedl syndrome, where hearing thresholds were reported to be subclinically increased in a group of adolescents patients, we recommend follow-up of JBS patients in view of the possibility of progressive, late-onset SNHL. [Copyright &y& Elsevier]

Abstract: We report on a male patient with intra-uterine growth retardation, microcephaly, coloboma, laryngomalacia and developmental delay. Array CGH analysis revealed a 649kb duplication on chromosome 1p34.1. Only five patients with overlapping duplications have been reported thus far. Ten known genes are located in the duplicated region, including the POMGNT1 gene encoding for O-mannose beta-1,2-N-acetylglucosaminyltransferase. This gene, mutated in muscle–eye–brain disease, might be causative for the observed phenotype in our patient. [Copyright &y& Elsevier]