Fluid Transport Model Research Articles

Carbonic Anhydrase Inhibitors in Corneal Endothelial Transport

Carbonic anhydrases play a central buffering role in current models of fluid transport in corneal endothelium, but in humans, clinical use of carbonic anhydrase inhibitors (CAIs) for the management of glaucoma does not cause corneal swelling. This study compares species differences in response to CAIs in human versus bovine corneal endothelial transport. Short-circuit current (Isc) measurements were performed on bovine and human corneal endothelium under identical conditions. The effects of four CAIs (acetazolamide, brinzolamide, dorzolamide, and ethoxzolamide) were measured. Endothelial expression of carbonic anhydrase II and IV was evaluated by immunofluorescence microscopy. Functional presence of carbonic anhydrase activity was determined using the Hansson's cobalt sulfide histochemical method. All four CAIs decreased bovine Isc (% change in Isc: acetazolamide, -21.0 ± 9.5, n = 8; brinzolamide, -35.5 ± 13.5, n = 9; dorzolamide, -33.6 ± 7.2, n = 8; ethoxzolamide, -35.3 ± 12.9, n = 8). That decrease was not present in humans (% change in Isc: acetazolamide, 16.2 ± 20.1, n = 3; brinzolamide, 6.7 ± 13.9, n = 3; dorzolamide, 8.0 ± 20.4, n = 3; ethoxzolamide, -4.8 ± 10.3, n = 2). Despite no functional effect of CAIs on Isc, both carbonic anhydrase II and IV were present in human corneal endothelium by immunofluorescence microscopy. Histochemical analysis of human corneal endothelium revealed functionally active carbonic anhydrase activity inhibited by brinzolamide. Carbonic anhydrase facilitates ion transport impacting the corneal endothelial Isc in bovine but not human corneal endothelium, despite its presence and functional activity in human tissue. This finding supports the clinical observation of no corneal swelling in humans administered CAIs and suggests that alternative ion transport mechanisms may be operational in corneal endothelium of different species.

Measuring miscible fluid displacement in porous media with magnetic resonance imaging

AbstractThe development of new quantitative magnetic resonance imaging (MRI) technologies open new opportunities for measurements of mass transport in porous media. The current work examines a simple miscible displacement process of H2O and D2O in porous media samples. Laboratory measurements of dispersion in porous media traditionally monitor the effluent intensity of an injected tracer. We employ MRI to obtain quantitative water saturation profiles, and to measure dispersion in rock core plugs. The saturation profiles are modeled with PHREEQC, a fluid transport modeling program. We demonstrate how independent magnetic resonance measurements can be employed to estimate three important input parameters for PHREEQC, mobile porosity, immobile porosity, and dispersivity. Bulk Carr Purcell Meiboom Gill (CPMG) T2 distribution measurements were undertaken to estimate mobile and immobile porosity. Bulk alternating‐pulsed‐gradient‐stimulated‐echo (APGSTE) measurements were undertaken to measure dispersivity. The imaging method employed, T2 mapping Spin Echo Single Point Imaging (SE‐SPI), also provides information about the pore size distributions in the rock cores, and how the fluid occupancy of the pores changes during the displacement process.

The impact of porosity waves on crustal reaction progress and CO2 mass transfer

Rocks below the brittle-ductile transition can deform viscously and compact while fluid percolates through (two-phase solid–fluid flow). We investigate chemical reaction systematics during two-phase flow using one-dimensional numerical models in which reactive H2O–CO2 fluid ascends down-temperature toward the surface, driving the retrograde reaction: 7CO2+3Calcite+Tremolite=5Dolomite+8Quartz+H2O. The reaction progress is compared to that predicted by fluid–rock reaction during “standard” Darcian flow. A range of layer thicknesses (km-scale) in one- and two-layer systems were investigated at pressure–temperature conditions below the brittle-ductile transition corresponding to ∼13–20 km depth. Model porosity waves of wavelength ∼5 km were generated repeatedly at the base of the flow region using a solitary wave solution with a prescribed initial wave amplitude A = (maximum porosity)/(background porosity of 10−3).Simulation of reaction progress and carbon transfer for the Darcian flow model and for porosity wave transport with A=5, 2.5 and 1.25 yield the following results. First, the overall reaction progress in the two fluid transport models is mainly controlled by the time-integrated fluid flux, and is not strongly dependent on the flow regime. The implication is that the fluid pressure gradient anomalies in the regional-scale porosity waves modeled herein play a negligible role in driving reaction progress. Second, although there are high fluid velocities and thus strong advection in large amplitude porosity waves, the kinetic parameters adopted from experiments predict that the fluid compositions approach local fluid–rock equilibrium in both transport models. Third, regional-scale carbonate-bearing rock layers may be substantial sinks for carbon in ascending fluids if sufficient porosity and permeability can be maintained during reaction. Finally, typical models of retrograde reactions predict that porosity ultimately becomes clogged and, thus, fluid flow is hindered. However, porosity wave transport provides a potential mechanism for creating new porosity to sustain fluid flow during retrogression.

Model based decision support system for the heap leaching process

As one of the copper recovery processes, hydrometallurgy has gain impact due to its ability to process ore with average low grades at competitive prices compared with other metallurgical processes. Among hydrometallurgical processes the leaching stage, a process that is characterized by its significant temporal and spatial scale of operation, is critical. In spite of extensive developments in instrumentation in pyrometullurgical and concentrators plants, developments in heap leaching instrumentation has not reached the required level for a fully automated control system and furthermore for a stable operation. Computational tools, such us dynamic simulators, can help operators achieve the best performance of the heap using the available instrumentation. This paper presents the development and implementation of an integrated dynamic simulator and a decision support system (DSS) for hydrometallurgical processes with emphasis in heap leaching process. The dynamic simulator uses two dimensional models of fluid transport, transport of solutes and dissolution of copper in the leaching heap, to analyse the effects produced in the variables of interest, such as the consumption of acid, copper concentration in the PLS (Pregnant Leach Solution) and leaching times. The DSS, which is connected to the real time plant information system, gathers the information by sensors and laboratory analyses to perform an automatic on-line parameter estimation of the process and makes predictions to recommend to the operator both curing and leaching rates. Results show that the DSS achieves the identification and prediction with less than 6% of error, allowing the metallurgist to predict the leaching behaviour and take decisions with better information.

Hydration adjacent to a deeply subducting slab: The roles of nominally anhydrous minerals and migrating fluids

AbstractSubduction‐related transport of water into the mantle has significant dynamical and geochemical implications. Dehydration of hydrous phases within the slab can introduce water into the transition zone and lower mantle, potentially hydrating nominally anhydrous minerals (NAM) and impacting the viscosity and density structure of the mantle over a wide area. We present models of fluid transport and mantle hydration in the vicinity of a deeply subducting slab, focusing on the fate of water released by deep dehydration reaction in the subducted serpentinized mantle. A sharp decrease in water storage capacity across the lower boundary of the transition zone may produce “secondary dehydration” of hydrated NAM, leading to precipitation of a hydrous fluid and heterogeneous hydration of the transition zone. Rapid fluid migration relative to the solid flow field can lead to a broad region of diffuse hydration within the upper mantle wedge and the potential for localized melt regions at the top of the transition zone coincident with fluid pathways. Slower fluid migration instead implies that the fluid phase can be transported deep into the lower mantle. Water stabilized in NAM and as a free fluid can initiate upwelling within and above the transition zone. A less abrupt change in water storage capacity across the base of the transition zone leads to high NAM water contents in a channel adjacent to the slab where viscosity is reduced. However, seismic and electromagnetic observations of hydration in the transition zone are most compatible with a sudden drop of water storage capacity.

Methane Hydrate and Two-Dimensional Fluid Transport Model: Comparison with Blake Ridge Chlorinity Measurements

The potential benefits and risks of natural methane hydrate occurrences have raised the need to understand the processes governing hydrate formation and dissociation over the last decades, and models of increasing complexity have been developed for this purpose. We propose a formulation of a multi-dimensional methane hydrate model that couples the established chemistry of hydrate formation to the fluid flow in marine sediments undergoing compaction. The numerical model applies the Finite Volume Method to construct a segregated solver for the coupled system. The solution of the sequence of individual processes is stabilised with an adaptive Picard iteration in each time step. We implement the model based on the OpenFOAM library and extend the functionality by generalising the diffusion term to take into account variable porosity of the sediment matrix. The advantage of this robust and efficient scheme is that the formulation is conservative by construction, allowing an accurate solution of mass transport when strong concentration gradients develop in the vicinity of phase boundaries. We validate the model using data from the Blake Ridge hydrate province. Good agreement is found for the pore water chlorinity, a proxy for hydrate formation, except for regions where heterogeneous hydrate formation results in highly variable measurements.

Validation studies of gyrofluid and gyrokinetic predictions of transport and turbulence stiffness using the DIII-D tokamak

A series of carefully designed validation experiments conducted on DIII-D to rigorously test gyrofluid and gyrokinetic predictions of transport and turbulence stiffness in both the ion and electron channels have provided an improved assessment of the experimental fidelity of those models over a range of plasma parameters. The first set of experiments conducted was designed to test predictions of H-mode core transport stiffness at fixed pedestal density and temperature. In low triangularity lower single null plasmas, a factor of 3 variation in neutral beam injection (NBI) heating was obtained, with modest changes to pedestal conditions that slowly increased with applied heating. The measurements and trends with increased NBI heating at both low and high injected torque are generally well-reproduced by the quasilinear trapped gyro-Landau fluid (TGLF) transport model at the lowest heating levels, but with decreasing fidelity (particularly in the electron profiles) as the heating power is increased. Complementing these global stiffness studies, a second set of experiments was performed to quantify the relationship between the local electron energy flux Qe and electron temperature gradient by varying the deposition profile of electron cyclotron heating about a specified reference radius in low density, low current L-mode plasmas. Modelling of these experiments using both the TGLF model and the nonlinear gyrokinetic GYRO code yields systematic underpredictions of the measured fluxes and fluctuation levels.

Textural versus electrostatic exclusion‐enrichment effects in the effective chemical transport within the cortical bone: A numerical investigation

Interstitial fluid within bone tissue is known to govern the remodelling signals' expression. Bone fluid flow is generated by skeleton deformation during the daily activities. Due to the presence of charged surfaces in the bone porous matrix, the electrochemical phenomena occurring in the vicinity of mechanosensitive bone cells, the osteocytes, are key elements in the cellular communication. In this study, a multiscale model of interstitial fluid transport within bone tissues is proposed. Based on an asymptotic homogenization method, our modelling takes into account the physicochemical properties of bone tissue. Thanks to this multiphysical approach, the transport of nutrients and waste between the blood vessels and the bone cells can be quantified to better understand the mechanotransduction of bone remodelling. In particular, it is shown that the electrochemical tortuosity may have stronger implications in the mass transport within the bone than the purely morphological one.

A simple mechanism for mid-crustal shear zones to record surface-derived fluid signatures

Research Article| June 01, 2013 A simple mechanism for mid-crustal shear zones to record surface-derived fluid signatures Tom Raimondo; Tom Raimondo * 1School of Natural and Built Environments, University of South Australia, GPO Box 2471, Adelaide, SA 5001, Australia2School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia *E-mail: tom.raimondo@unisa.edu.au. Search for other works by this author on: GSW Google Scholar Chris Clark; Chris Clark 3Department of Applied Geology, Curtin University, GPO Box U1987, Perth, WA 6845, Australia Search for other works by this author on: GSW Google Scholar Martin Hand; Martin Hand 2School of Earth and Environmental Sciences, University of Adelaide, Adelaide, SA 5005, Australia Search for other works by this author on: GSW Google Scholar John Cliff; John Cliff 4Centre for Microscopy, Characterisation and Analysis, University of Western Australia, Crawley, WA 6009, Australia Search for other works by this author on: GSW Google Scholar Robert Anczkiewicz Robert Anczkiewicz 5Institute of Geological Sciences, Polish Academy of Sciences, Kraków Research Centre, Senacka 1, PL 31002 Kraków, Poland Search for other works by this author on: GSW Google Scholar Geology (2013) 41 (6): 711–714. https://doi.org/10.1130/G34043.1 Article history received: 14 Sep 2012 rev-recd: 29 Jan 2013 accepted: 30 Jan 2013 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Tom Raimondo, Chris Clark, Martin Hand, John Cliff, Robert Anczkiewicz; A simple mechanism for mid-crustal shear zones to record surface-derived fluid signatures. Geology 2013;; 41 (6): 711–714. doi: https://doi.org/10.1130/G34043.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Ion microprobe analyses of garnet porphyroblasts from three separate splays of the mid-crustal Walter-Outalpa shear zone, Curnamona Province, South Australia, indicate homogeneous δ18O values of <3‰. Integrated Lu-Hf geochronology and electron microprobe compositional mapping demonstrate that closed-system growth of these isotopically light garnets initiated as early as 531 Ma, prior to peak metamorphism and deformation during the Delamerian Orogeny (514–490 Ma). We attribute this to the prograde burial and dehydration of altered fault panels under thick sedimentary sequences during pre-orogenic basin formation. Contrary to established fluid transport models, surficial fluid signatures were not imposed at depth by large fluxes of downward-penetrating fluids, but rather by the exposure and meteoric alteration of fault rocks that were subsequently buried and reactivated as ductile shear zones. The existence of low δ18O values in deeply exhumed shear zones may therefore be indicative of fault structures that have a prior history of surface exposure, weathering, burial and re-exposure. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Advances in Fluid and Thermal Transport Property Analysis and Design of Sintered Porous Wick Microstructures

Sintered porous structures are ubiquitous as heat transport media for thermal management and other applications. In particular, low-porosity sintered packed beds are used as capillary-wicking and evaporation-enhancement structures in heat pipes. Accurate prediction and analysis of their transport characteristics for different microstructure geometries is important for improved design. Owing to the random nature and geometric complexity of these materials, development of predictive methods has been the subject of extensive prior research. The present work summarizes and builds upon past studies and recent advances in pore-scale modeling of fluid and thermal transport within such heterogeneous media. A brief review of various analytical and numerical models for simplified prediction of transport characteristics such as effective thermal conductivity, permeability, and interfacial heat transfer is presented. More recently, there has been a growing interest in direct numerical simulation of transport in realistic representations of the porous medium geometry; for example, by employing nondestructive 3D imaging techniques such as X-ray microtomography. Future research directions are identified, looking beyond techniques intended for material characterization alone, and focusing on those targeting the reverse engineering of wick structures via modeling of the physical sintering fabrication processes. This approach may eventually be employed to design intricate sintered porous structures with desired properties tailored to specific applications.

3D analysis, modeling and simulation of transport processes in compressed fibrous microstructures, using the Lattice Boltzmann method

In this paper we combine a stochastic 3D microstructure model of a fiber based gas diffusion layer of polymer electrolyte fuel cells with a Lattice Boltzmann model for fluid transport. We focus on a simple approach of compressing the planar oriented virtual geometry of paper-type gas diffusion layer from Toray. Material parameters – permeability and tortuosity – are calculated from simulation of one phase, one component gas flow in stochastic geometries. We analyze the statistical spread of simulation results on ensembles of the virtual geometry, both uncompressed and compressed. The influence of the compression is discussed with regard to the Kozeny–Carman equation. The effective transport properties calculated from transport simulations in compressed gas diffusion layers agree well with a trend based on the Kozeny–Carman equation.

Control and optimization of solute transport in a thin porous tube

Predicting the distribution of solutes or particles in flows within porous-walled tubes is essential to inform the design of devices that rely on cross-flow filtration, such as those used in water purification, irrigation devices, field-flow fractionation, and hollow-fibre bioreactors for tissue-engineering applications. Motivated by these applications, a radially averaged model for fluid and solute transport in a tube with thin porous walls is derived by developing the classical ideas of Taylor dispersion. The model includes solute diffusion and advection via both radial and axial flow components, and the advection, diffusion, and uptake coefficients in the averaged equation are explicitly derived. The effect of wall permeability, slip, and pressure differentials upon the dispersive solute behaviour are investigated. The model is used to explore the control of solute transport across the membrane walls via the membrane permeability, and a parametric expression for the permeability required to generate a given solute distribution is derived. The theory is applied to the specific example of a hollow-fibre membrane bioreactor, where a uniform delivery of nutrient across the membrane walls to the extra-capillary space is required to promote spatially uniform cell growth.

The effect of temperature and moisture on the mechanical properties of extruded cornstarch

AbstractThe viscoelastic properties of extruded cornstarch were measured as a function of process conditions. The extruded cornstarch samples were conditioned in the moisture range of 12.9–31.2% (dry basis). Dynamic and creep behavior of the extrudate were evaluated using a dynamic mechanical analyzer. The storage (G′) and loss moduli (G″) were determined in the temperature range of 30–100C and oscillation frequency range of 0.1–51 Hz. The G′ and G″ values showed an increasing trend with a decrease in temperature and moisture content and an increase in frequency. This implied an increase in solid‐like behavior when the temperature and moisture content were reduced or the frequency was increased. Rheological parameters based on creep behavior were assessed at 30, 60 and 85C. Creep data, fitted using Burger's model, were highly dependent on both moisture content and temperature.Practical ApplicationsThe viscoelastic properties obtained in this experimental research can be used for solving the non‐Fickian fluid transport model for studying the expansion of starch during extrusion. The viscoelastic properties also provide an indication about the textural characteristics of starch as a function of extrusion conditions.

Giant osmotic energy conversion measured in a single transmembrane boron nitride nanotube

New models of fluid transport are expected to emerge from the confinement of liquids at the nanoscale, with potential applications in ultrafiltration, desalination and energy conversion. Nevertheless, advancing our fundamental understanding of fluid transport on the smallest scales requires mass and ion dynamics to be ultimately characterized across an individual channel to avoid averaging over many pores. A major challenge for nanofluidics thus lies in building distinct and well-controlled nanochannels, amenable to the systematic exploration of their properties. Here we describe the fabrication and use of a hierarchical nanofluidic device made of a boron nitride nanotube that pierces an ultrathin membrane and connects two fluid reservoirs. Such a transmembrane geometry allows the detailed study of fluidic transport through a single nanotube under diverse forces, including electric fields, pressure drops and chemical gradients. Using this device, we discover very large, osmotically induced electric currents generated by salinity gradients, exceeding by two orders of magnitude their pressure-driven counterpart. We show that this result originates in the anomalously high surface charge carried by the nanotube's internal surface in water at large pH, which we independently quantify in conductance measurements. The nano-assembly route using nanostructures as building blocks opens the way to studying fluid, ionic and molecule transport on the nanoscale, and may lead to biomimetic functionalities. Our results furthermore suggest that boron nitride nanotubes could be used as membranes for osmotic power harvesting under salinity gradients.

Flux of volcanic CO2 emission estimated from melt inclusions and fluid transport modelling

Volcanic CO2 degassing is considered the primary process that controls the global carbon cycle over geological timescales. However, fluxes of CO2 from individual volcanoes, in particular those in past activities, have been poorly constrained. One way to estimate the flux is by using the H2OCO2 systematics of melt inclusions, which, according to petrological studies, records fluxing of a deep-derived CO2-rich fluid in the deep to shallow-level crustal magmatic systems. Assuming that this fluid fluxing is the process of volcanic CO2 emission, we quantified the fluxes of CO2 by combining a fluid transport model with melt inclusion data. We formulated CO2 fluxing as an advective fluid flow in a basaltic magma column with exchanging volatiles, and applied it to the melt inclusion data from Mount Etna, the type locality of a CO2-emitting volcano. The flux of CO2 was calculated to be 2.4–6.0kt/day, which is consistent with the observed volcanic CO2 emission rate of 1–10kt/day. We propose that this method potentially provides a means to quantify CO2 emission rates in past volcanic activities. Because CO2 fluxing is an open-system process, the estimated CO2 emission over geological timescales evaluated with this method should give much higher values than evaluations based simply on the volume of the erupted magmas.

A mixture theory model of fluid and solute transport in the microvasculature of normal and malignant tissues. II: Factor sensitivity analysis, calibration, and validation

The treatment of cancerous tumors is dependent upon the delivery of therapeutics through the blood by means of the microcirculation. Differences in the vasculature of normal and malignant tissues have been recognized, but it is not fully understood how these differences affect transport and the applicability of existing mathematical models has been questioned at the microscale due to the complex rheology of blood and fluid exchange with the tissue. In addition to determining an appropriate set of governing equations it is necessary to specify appropriate model parameters based on physiological data. To this end, a two stage sensitivity analysis is described which makes it possible to determine the set of parameters most important to the model's calibration. In the first stage, the fluid flow equations are examined and a sensitivity analysis is used to evaluate the importance of 11 different model parameters. Of these, only four substantially influence the intravascular axial flow providing a tractable set that could be calibrated using red blood cell velocity data from the literature. The second stage also utilizes a sensitivity analysis to evaluate the importance of 14 model parameters on extravascular flux. Of these, six exhibit high sensitivity and are integrated into the model calibration using a response surface methodology and experimental intra- and extravascular accumulation data from the literature (Dreher etal. in J Natl Cancer Inst 98(5):335-344, 2006). The model exhibits good agreement with the experimental results for both the mean extravascular concentration and the penetration depth as a function of time for inert dextran over a wide range of molecular weights.

Influence of thermohaline effects on groundwater modelling – Application to the Paris sedimentary Basin

Summary In the framework of evaluating the safety of a radioactive waste disposal in deep argillaceous formations and its assessment by the implementer, IRSN and MINES ParisTech built a hydrogeological model of the Paris Basin aquifer system with the aim of identifying radionuclide pathways, estimating transfer times associated with those pathways and locating potential outlets. Such modelling of fluid and mass transport through a sedimentary basin is a recurrent applied geology study. However, recent research shows that in a deep and saline environment, density effects induced by both temperature (to a small extent) and particularly salt concentration can play a major role in the predicted groundwater flow pathways. The present study highlights the relevance of building a hydrogeological model from the measured hydrogeological and hydrogeochemical parameters by combining the calibration of the piezometric levels and the salinity values simultaneously. The application of this strategy to the Paris Basin shows that the Keuper halite formation (Triassic), located in the eastern part of the basin, can be considered as the unique salt source, provided that the density effects are taken into account in the flow and transport modelling. The calibration requires, in particular, to also take into account some of the basin’s major tectonic faults, which allow vertical hydraulic connections between aquifers and thus allow salt water fluxes toward the shallower formations. The results presented in this paper show that when considering “thermohaline” effects, the model effectively reproduces the observed hydraulic heads and salinity values throughout the entire Paris Basin, whilst at the same time outlining the role of faults and of the geometry of geological formations on salt transport.

A mixture theory model of fluid and solute transport in the microvasculature of normal and malignant tissues. I. Theory

In order to better understand the mechanisms governing transport of drugs, nanoparticle-based treatments, and therapeutic biomolecules, and the role of the various physiological parameters, a number of mathematical models have previously been proposed. The limitations of the existing transport models indicate the need for a comprehensive model that includes transport in the vessel lumen, the vessel wall, and the interstitial space and considers the effects of the solute concentration on fluid flow. In this study, a general model to describe the transient distribution of fluid and multiple solutes at the microvascular level was developed using mixture theory. The model captures the experimentally observed dependence of the hydraulic permeability coefficient of the capillary wall on the concentration of solutes present in the capillary wall and the surrounding tissue. Additionally, the model demonstrates that transport phenomena across the capillary wall and in the interstitium are related to the solute concentration as well as the hydrostatic pressure. The model is used in a companion paper to examine fluid and solute transport for the simplified case of an axisymmetric geometry with no solid deformation or interconversion of mass.

A study on the sealing ability and antibacterial activity of Ca3SiO5/CaCl2 composite cement for dental applications

The objective of this study was to evaluate the sealing ability and antibacterial activity of Ca3SiO5/CaCl2 composite cement. Fifty maxillary anterior teeth were instrumented according to step-back technique and filled with experimental and control materials. To evaluate the sealing ability, a fluid transport model using glucose was employed for quantitative analysis of endodontic microleakage. To evaluate antibacterial activity, E. colias (ATCC 25922) was cultivated on agar plates. Results showed that the sealing ability of Ca3SiO5/CaCl2 composite cement and cortisomol paste were higher than that of zinc oxide-eugenol (ZOE) cement, and that no significant difference was observed between Ca3SiO5/CaCl2 composite cement and cortisomol paste. On antibacterial activity, Ca3SiO5/CaCl2 composite cements composed of varying amounts of CaCl2 (0-15%) exhibited similar levels of activity against E. coliasas calcium hydroxide cement, whereas cortisomol paste had little effect on E. colias. All these results suggested that Ca3SiO5/CaCl2 composite cement demonstrated good potential for root canal treatment applications.

&lt;I&gt;In vitro &lt;/I&gt;permeability of etch-and-rinse and self-etch adhesives used for immediate dentin sealing

To investigate the permeability of deep dentin following immediate sealing with different etch-and-rinse and self-etch adhesives (Single Bond 2, Adper Prompt L-Pop, Clearfil Protect Bond, Clearfil S3 Bond, G-Bond) and a dentin desensitizer (Gluma). Fluid-transport model was used to measure fluid conductance during and after application of adhesives. Polyvinylsiloxane impressions of bonded dentin were taken to monitor fluid transudation from the surface of the adhesives. The area and number of dentinal fluid droplets and/or blisters were calculated using image analysis. None of the adhesives were able to block fluid conductance completely. The fluid conductance values of the adhesives displayed the following statistical ranking (p<0.05): G-Bond≤Clearfil Protect Bond<Smear-layer-covered dentin<S3 Bond≤Single Bond 2≤Adper Prompt L-Pop<Gluma Desensitizer<Acid-etched dentin. Highly significant correlation was observed between the permeability of the tested adhesives and the area fraction of fluid droplets/blisters on the adhesive surfaces (r=0.99, p<0.01).