Interface Fluid Research Articles

Active storage machine can unveil previous LASIK surgery by reproducing ex vivo interface fluid syndrome during eye banking

Active storage machine can unveil previous LASIK surgery by reproducing ex vivo interface fluid syndrome during eye banking

Transport of topological defects in a biphasic mixture of active and passive nematic fluids

Collectively moving cellular systems often contain a proportion of dead cells or non-motile genotypes. When mixed, nematically aligning motile and non-motile agents are known to segregate spontaneously. However, the role that topological defects and active stresses play in shaping the distribution of the two phases remains unresolved. In this study, we investigate the behaviour of a two-dimensional binary mixture of active and passive nematic fluids to understand how topological defects are transported between the two phases and, ultimately, how this leads to the segregation of topological charges. When the activity of the motile phase is large, and the tension at the interface of motile and non-motile phases is weak, we find that the active phase tends to accumulate +1/2 defects and expel −1/2 defects so that the motile phase develops a net positive charge. Conversely, when the activity of the motile phase is comparatively small and interfacial tension is strong, the opposite occurs so that the active phase develops a net negative charge. We then use these simulations to develop a physical intuition of the underlying processes that drive the charge segregation. Lastly, we quantify the sensitivity of this process on the other model parameters, by exploring the effect that anchoring strength, orientational elasticity, friction, and volume fraction of the motile phase have on topological charge segregation. As +1/2 and −1/2 defects have very different effects on interface morphology and fluid transport, this study offers new insights into the spontaneous pattern formation that occurs when motile and non-motile cells interact.

Topographic variation and fluid flow characteristics in rough contact interface

Understanding flow characteristics of fluid near rough contact is important for the design of fluid-based lubrication and basic of tribology physics. In this study, the spreading and seepage processes of anhydrous ethanol in the interface between glass and rough PDMS are observed by a homemade optical in-situ tester. Digital image processing technology and numerical simulation software are adapted to identify and extract the topological properties of interface and thin fluid flow characteristics. Particular attention is paid to the dynamic evolution of the contact interface morphology under different stresses, the distribution of microchannels in the interface, the spreading characteristics of the fluid in contact interface, as well as the mechanical driving mechanism. Original surface morphology and the contact stress have a significant impact on the interface topography and the distribution of interfacial microchannels, which shows that the feature lengths of the microchannels, the spreading area and the spreading rate of the fluid are inversely proportional to the load. And the flow path of the fluid in the interface is mainly divided into three stages: along the wall of the island, generating liquid bridges, and moving from the tip side to the root side in the wedge-shaped channel. The main mechanical mechanism of liquid flow in the interface is the equilibrium between the capillary force that drives the liquid spreading and viscous resistance of solid wall to liquid. In addition, the phenomenon of “trapped air” occurs during the flow process due to the irregular characteristics of the microchannel. This study lays a certain theoretical foundation for the research of microscopic flow behavior of the liquid in the rough contact interface, the friction and lubrication of the mechanical system, and the sealing mechanism.

Letter Regarding: Corneal Edema as the Sine Qua Non Factor in the Pathophysiology of Interface Fluid Syndrome.

Letter Regarding: Corneal Edema as the Sine Qua Non Factor in the Pathophysiology of Interface Fluid Syndrome.

Compression sutures alone to treat acute hydrops in a case of post-laser in situ keratomileusis ectasia and review of literature

This is a case report of acute hydrops in a patient with post-laser in situ keratomileusis (LASIK) ectasia treated with compression sutures. A patient with post-LASIK ectasia presented with acute hydrops in the left eye. Full-thickness compression sutures were applied to appose the edges of the Descemet tear, and this resulted in a rapid resolution of stromal edema and interface fluid. The patient had the best distance visual acuity of 6/18 at the last follow-up. Compression sutures only were useful in this case to hasten the resolution of stromal edema and interface fluid.

Delayed interface fluid syndrome in a post laser-assisted in situ keratomileusis: A rare complication

Interface fluid syndrome (IFS) is a rare complication seen post-laser-assisted in situ keratomileusis (post-LASIK). This report describes two unusual cases in which patients underwent ocular surgeries and developed delayed onset interface fluid. Both the patients had undergone uneventful laser-assisted in situ keratomileusis (LASIK) decades ago; case 1 underwent uneventful phacoemulsification and vitrectomy with gas tamponade and case 2 underwent uneventful phacoemulsification with intraocular lens implantation. Possible causes of IFS could be steroid-induced intraocular pressure (IOP) spike, intraocular inflammation, or both. IFS can be seen any time after refractive surgeries and can be a lifelong complication after LASIK surgery. Inaccurate IOP measurement due to underestimation should be borne in mind while measuring IOP in such patients. This report highlights the challenges in diagnosing IFS and the importance of correct IOP measurement in such cases to avoid irreversible vision loss.

Pore-scale investigation of forced imbibition in porous rocks through interface curvature and pore topology analysis

Forced imbibition, the invasion of a wetting fluid into porous rocks, plays an important role in the effective exploitation of hydrocarbon resources and the geological sequestration of carbon dioxide. However, the interface dynamics influenced by complex topology commonly leads to non-wetting fluid trapping. Particularly, the underlying mechanisms under viscously unfavorable conditions remain unclear. This study employs a direct numerical simulation method to simulate forced imbibition through the reconstructed digital rocks of sandstone. The interface dynamics and fluid–fluid interactions are investigated through transient simulations, while the pore topology metrics are introduced to analyze the impact on steady-state residual fluid distribution obtained by a pseudo-transient scheme. The results show that the cooperative pore-filling process promoted by corner flow is dominant at low capillary numbers. This leads to unstable inlet pressure, mass flow, and interface curvature, which correspond to complicated interface dynamics and higher residual fluid saturation. During forced imbibition, the interface curvature gradually increases, with the pore-filling mechanisms involving the cooperation of main terminal meniscus movement and arc menisci filling. Complex topology with small diameter pores may result in the destabilization of interface curvature. The residual fluid saturation is negatively correlated with porosity and pore throat size, and positively correlated with tortuosity and aspect ratio. A large mean coordination number characterizing global connectivity promotes imbibition. However, high connectivity characterized by the standardized Euler number corresponding to small pores is associated with a high probability of non-wetting fluid trapping.

An Enigmatic Fluid Accumulation Following Descemet Membrane Endothelial Keratoplasty After Prior Laser In Situ Keratomileusis

Purpose: To report a case of interface fluid syndrome (IFS) following Descemet membrane endothelial keratoplasty (DMEK) 13 years after laser in situ keratomileusis (LASIK). Methods: A 79-year-old patient with bullous keratopathy underwent uneventful DMEK. Thirteen years prior, he had undergone LASIK. After DMEK, he developed an IFS, which was confirmed by a fluid accumulation in the flap interface, visible in the anterior segment optical coherence tomography (AS-OCT). In this case, IFS is presumed to have been triggered by the corticosteroid eye drops administered postoperatively. Measurements of the intraocular pressure (IOP) via applanation tonometry yielded erroneously low results. Results: The discontinuation of the corticosteroid eye drops, along with the initiation of IOP-lowering therapy, led to an improvement in fluid accumulation and a decrease in IOP. Regular ophthalmic examinations with a palpatory assessment of IOP and monitoring of fluid via AS-OCT are recommended. In this case, no more fluid could be detected in the flap interface after 14 months, and IOP was normal. Conclusions: IFS can occur many years after LASIK treatment. Corticosteroids should be discontinued, and IOP-lowering therapy should be initiated to prevent irreversible damage to the optic nerve. Applanation tonometry leads to inaccurately low IOP measurements; therefore, a palpatory assessment of IOP is recommended. AS-OCT is a crucial imaging modality that should be employed for monitoring.

Evaluating wave force and interface fluid velocity distribution at the vicinity of a breakwater by considering consolidation of porous media

Previous studies have successfully simulated the interaction between wave and porous media using volume-averaged Reynolds-averaged Navier-Stokes (VARANS) equations. However, the consolidation of porous media subject to wave loading affects the progressing wave, which is crucial to computation of wave force and wave-porous media interface fluid velocity. Research on this aspect is scarce. This study adopted the u -p approximation for Biot dynamic consolidation theory to quantify the consolidation of porous media. The continuity condition on the interfaces between the wave and porous seabed was considered to achieve their interaction. Coupling algorithms of wave and porous seabed were validated against experimental measurements in the literature. An engineering case of wave traveling over a breakwater was examined, and computation results of wave pressures and interface fluid velocities at the vicinity of a breakwater by VARANS equations and wave-porous seabed coupling algorithm of this study were compared to explore the influence of the consolidation effect on the progressing wave.

Erratum to: Interface fluid syndrome after LASIK surgery: retrospective pooled analysis and systematic review.

Erratum to: Interface fluid syndrome after LASIK surgery: retrospective pooled analysis and systematic review.

Descemet Membrane Endothelial Keratoplasty as Treatment for Late-Onset Interface Fluid Syndrome After Laser In Situ Keratomileusis.

We herein present Descemet membrane endothelial keratoplasty (DMEK) as an effective surgical means of treatment for the management of interface fluid syndrome (IFS) in a series of cases with distant history of laser in situ keratomileusis (LASIK). Three cases from a single institution were included. All patients had documented IFS in the setting of history of LASIK. All 3 patients underwent DMEK for the treatment of IFS. Visual acuity, clinical findings, pachymetry, endothelial cell count, and anterior segment optical coherence tomography were recorded. We describe 3 cases of late-onset IFS that developed in eyes many years after LASIK (ranging from 15 to 31 years). All 3 patients had clinically significant corneal edema and evidence of poor endothelial function at the time of IFS diagnosis. DMEK was subsequently performed in each case. All 3 eyes showed resolution of corneal edema and improvement in best-corrected visual acuity after DMEK. DMEK can provide successful visual and anatomical recovery in patients who have had previous LASIK and experience late-onset IFS due to endothelial cell dysfunction.

Interface fluid syndrome caused by the corneal perforation injury after small incision lenticule extraction: a case report

BackgroundTo report a case of interface fluid syndrome (IFS) following traumatic corneal perforation repair after small incision lenticule extraction (SMILE).Case presentationA 23-year-old woman, with a past history of SMILE, was struck in the left eye with a barbecue prod and subsequently underwent corneal perforation repair at local hospital. Primary wound repaired with a single 10 − 0 nylon suture at the area of leakage. After the surgery, her best corrected visual acuity (BCVA) was 20/30. Four days later, she presented at our hospital with blurred vision, and interface fluid syndrome (IFS) was diagnosed. Intraoperative optical coherence tomography (iOCT) was used to guide the resuturing of the corneal perforation in the left eye, followed by anterior chamber gas injection. At the first postoperative month, the BCVA was 20/25. The corneal cap adhered closely to the stroma, the surface became smooth.ConclusionsThis case illustrates that any corneal perforation following lamellar surgery, including SMILE, may lead to IFS. It is crucial to consider the depth of corneal perforation, and intraoperative optical coherence tomography (iOCT) plays a unique role in the repair procedure.

A hydro-mechanical coupled contact method for two-phase geotechnical large deformation problems within the SNS-PFEM framework

This paper proposes a novel numerical algorithm to solve frictional contact problems in two-phase porous media, accounting for the large deformation and interface fluid flow, within the framework of the Stable Node-based Smoothed Particle Finite Element Method (SNS-PFEM). The proposed approach builds on our previous work that was only designed for single-phase large deformation contact problems. Within this work, the hydro-mechanical coupling system is discretized using equal-order interpolation, with a polynomial pressure projection method to eliminate the pore pressure instability. Surface-to-surface discretization is then applied to formulate the contact constraint of the two-phase porous medium. Using the dual Lagrange multiplier approach, a coordinate transformation is introduced to enforce the contact constraint of the solid phase. This transformation is subsequently utilized to develop a new interface fluid element, which serves as a tool to model the fluid exchange behaviour between porous media and contact gaps. Different from existing interface fluid elements, the proposed element is constructed based on the contact algorithm, thereby enabling it to handle non-conforming interfaces and tackle challenges associated with large sliding problems. Furthermore, the proposed method can maintain a well-conditioned system matrix throughout the computation process. These distinctive attributes significantly enhance the flexibility of numerical modelling. Finally, the accuracy and performance of our method are verified through four numerical examples. The results show that the proposed method can effectively simulate various geotechnical problems, including multi-layer soil consolidation, fluid-soil-structure interaction, and geological interface-controlled slope failure.

Multicomponent thermodynamics with instabilities and diffuse interfaces fluids

<p>We investigated the mathematical structure of Gibbsian multicomponent thermodynamics with instabilities. We analyzed the construction of such thermodynamics from a pressure law using ideal gases as the low density limit. The fluid mixtures were allowed to have mechanically and chemically unstable states that were excluded in previous work on supercritical fluids, and the Soave-Redlich-Kwong cubic equation of state was specifically considered. We also investigated the mathematical structure of extended thermodynamics in the presence of cohesive forces—capillary effects—for a simplified diffuse interface fluid model. The thermodynamic formalism was validated by comparison with experimental data for mixtures of ethane and nitrogen. Very good agreement with experimental data was obtained for specific heats, multiphase equilibrium, and critical points, and we also analyzed the structure of strained jets of ethane.</p>

Symmetrization and Local Existence of Strong Solutions for Diffuse Interface Fluid Models

Symmetrization and Local Existence of Strong Solutions for Diffuse Interface Fluid Models

Vertical transmission of African-lineage Zika virus through the fetal membranes in a rhesus macaque (Macaca mulatta) model.

Zika virus (ZIKV) can be transmitted vertically from mother to fetus during pregnancy, resulting in a range of outcomes including severe birth defects and fetal/infant death. Potential pathways of vertical transmission in utero have been proposed but remain undefined. Identifying the timing and routes of vertical transmission of ZIKV may help us identify when interventions would be most effective. Furthermore, understanding what barriers ZIKV overcomes to effect vertical transmission may help improve models for evaluating infection by other pathogens during pregnancy. To determine the pathways of vertical transmission, we inoculated 12 pregnant rhesus macaques with an African-lineage ZIKV at gestational day 30 (term is 165 days). Eight pregnancies were surgically terminated at either seven or 14 days post-maternal infection. Maternal-fetal interface and fetal tissues and fluids were collected and evaluated for ZIKV using RT-qPCR, in situ hybridization, immunohistochemistry, and plaque assays. Four additional pregnant macaques were inoculated and terminally perfused with 4% paraformaldehyde at three, six, nine, or ten days post-maternal inoculation. For these four cases, the entire fixed pregnant uterus was evaluated with in situ hybridization for ZIKV RNA. We determined that ZIKV can reach the MFI by six days after infection and infect the fetus by ten days. Infection of the chorionic membrane and the extraembryonic coelomic fluid preceded infection of the fetus and the mesenchymal tissue of the placental villi. We did not find evidence to support a transplacental route of ZIKV vertical transmission via infection of syncytiotrophoblasts or villous cytotrophoblasts. The pattern of infection observed in the maternal-fetal interface provides evidence of paraplacental vertical ZIKV transmission through the chorionic membrane, the outer layer of the fetal membranes.

Surfactant-influenced oil–water slip and flow in nanochannels studied by molecular dynamics and theoretical modeling

This work uses molecular dynamics (MD) methods to investigate oil–water two-phase flow in hydrophilic nanochannels with surfactants adsorbed at the oil–water interface. We reveal two new discontinuous effects of nanoscale fluid flow: (i) the velocity distribution in the water layer is not a univariate function of the pressure gradient, and (ii) the apparent viscosity in the oil–water interface region is a function of surfactant concentration and pressure gradient. Based on the MD results, a layered theoretical model describing the discontinuous effects at the nanoscale is developed. The theoretical model provides quantitative two-dimensional functions for oil–water interface slip and fluid mass flux with pressure gradient and surfactant concentration. Surfactants significantly inhibit oil–water slip and reduce fluid mass flux. This study thus provides important insights into the theoretical and numerical models for shale or tight oil production predictions.

Superspreading metal–organic frameworks modified interface for high-performance tritiated wastewater separation: Experiments and CFD simulation studies

The tritiated water distillation method can inherently safely treat tritiated wastewater, but the separation efficiency is low, and there is limited understanding of the gas–liquid two-phase countercurrent distillation process that affects its separation performance. In this study, tritiated water distillation experiments with metal–organic frameworks (MOFs)-modified superspreading interface and computational fluid dynamic (CFD) simulations were conducted to investigate the influence of contact angle on gas–liquid two-phase interfaces and liquid holdup, as well as its impact on separation performance. A distillation column with a length of 1 m had a smaller height equal to a theoretical plate (HETP) of 3.0 cm, and higher separation performance than non-modified packing with HETP of 7.2 cm. The volume of fluid (VOF) method with the high-resolution interface capturing (HRIC) scheme was used to reconstruct the gas–liquid interface and the accuracy of CFD simulating was validated by droplet spreading experiment. CFD simulations demonstrated that the gas–liquid interface area increased from 34.9 m2/m−3(−|−) to 498.5 m2/m−3(−|−) with the contact angle decreasing from 90° to 0°. When the reflux rate increases from 85 kg m−2h−1 to 425 kg m−2h−1, the liquid holding capacity of the column remains stable at about 10 %, and the phase interface area remains stable at about 500 m2/m−3(−|−) for the MOFs-modified column. This research increased the understanding of the influence of surface wetting on the performance of tritiated water distillation and had potential applications for other gas–liquid two-phase flow separation processes.

Modified diffuse interface fluid model and its consistent energy-stable computation in arbitrary domains

Binary fluid flows in irregular domains are common phenomena in natural and industrial fields. To describe these physical processes, we herein present a novel fluid flow-coupled two-material model reflecting different wetting conditions on an arbitrary fluid-solid interface. A modified ternary Cahn–Hilliard (CH) diffuse interface model is adopted to capture the fluid-fluid interface. One of three components is fixed for all time to represent the profile of complex domains. By considering the contact angle condition on solid-fluid interface and equilibrium interface assumption, an extra wetting term is derived. To treat the fluid flow in domains with solid obstacles, we consider the entire system as a porous medium with variable permeability and add a large penalty term into the incompressible Navier–Stokes (NS) equations. It can be proven that the proposed modified Cahn–Hilliard–Navier–Stokes (CHNS) system satisfies the energy dissipation law (energy stability). Based on the scalar auxiliary variable (SAV) approach with appropriate correction techniques, the linear and consistent energy-stable scheme is developed. We introduce the numerical implementation and estimate the discrete version of energy stability in detail. The proposed method can be implemented on regular Cartesian grids with the absence of explicit boundary treatment. Moreover, the calculations are totally decoupled in each time step. Extensive numerical experiments not only indicate the expected accuracy and stability but also show the superior performance in arbitrary domains with different wetting conditions.

Treatment of Interface Fluid Syndrome after Laser-Assisted In Situ Keratomileusis with Descemet Membrane Endothelial Keratoplasty in Three Patients with Corneal Endothelial Dysfunction

Treatment of Interface Fluid Syndrome after Laser-Assisted In Situ Keratomileusis with Descemet Membrane Endothelial Keratoplasty in Three Patients with Corneal Endothelial Dysfunction