REVIEW | doi:10.20944/preprints202301.0195.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: COVID-19; COVID-19 vaccines; capillary leak syndrome
Online: 11 January 2023 (09:41:36 CET)
Systemic capillary leak syndrome (SCLS) is an uncommon, potentially life-threatening disorder defined as recurrent attacks of pseudo-shock. This syndrome occurs due to the disruption of endothelial cells, which leads to increased vascular permeability, causing intravascular fluid to leak into the extravascular space and albumin to be retained in the interstitial space. SCLS can lead to hypovolemia, peripheral hypoperfusion, and acute renal insufficiency. The syndrome is presented with fever, generalized edema, pleural effusions, dyspnea, hypovolemia, hemoconcentration, prerenal azotemia, shock, and syncope. After ruling out other causes of hypovolemic shock, the diagnosis of SCLS can be considered on the presence of the classical triad of hypotension, hemoconcentration, and hypoalbuminemia. Eliminating the precipitating factors is the cornerstone of SCLS management. It is advisable to be very cautious and weigh the risks and benefits of vaccination of people with a history of this condition. This review will discuss and compare different aspects of SLCS after SARS-CoV-2 infection and COVID-19 vaccination.
ARTICLE | doi:10.20944/preprints202305.1406.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: Brain capillary endothelial cell(s)
Online: 19 May 2023 (08:15:17 CEST)
Brain capillary endothelial cell(s) (BECs) have numerous functions including their semipermeable interface-barrier (transfer and diffusion of solutes), trophic (metabolic homeostasis), tonic (vascular hemodynamics), and trafficking (vascular permeability, coagulation, and leukocyte extravasation) functions to provide brain homeostasis. BECs also serve as the brain’s sentinel cell of the innate immune system and are capable of antigen presentation. In metabolic syndrome (MetS) there are two regions resulting in proinflammatory signaling of BECs. Namely, visceral adipose tissue depots supplying excessive peripheral cytokines/chemokines (pCC) and gut microbiota dysbiotic regions supplying excessive soluble lipopolysaccharide (sLPS), small LPS-enriched extracellular vesicle exosomes (lpsEVexos), and pCC. This dual signaling of BECs at their receptor sites results in BEC activation and dysfunction (BECact/dys) and neuroinflammation. sLPS and lpsEVexos signal BECs toll-like receptor four, which then signals translocated nuclear factor kappa B (NFkB). Translocated NFkB promotes the synthesis and secretion of BEC proinflammatory cytokines and chemokines. Specifically, the chemokine CCL5 (RANTES) is capable of attracting microglia cells to BECs. BEC neuroinflammation activates perivascular space(s) (PVS) resident macrophages. Excessive phagocytosis by reactive resident PVS macrophages results in a stagnation-like obstruction, which along with increased capillary permeability due to BECact/dys could expand the fluid volume within the PVS to result in enlarged PVS (EPVS). Importantly, this remodeling may result in pre- and post-capillary EPVS that would contribute to their identification on T2-weighted MRI, which are considered to be biomarkers for cerebral small vessel disease.
ARTICLE | doi:10.20944/preprints202102.0360.v1
Subject: Physical Sciences, Fluids And Plasmas Physics Keywords: turbulence; capillary wave; spectrum; anisotropy
Online: 17 February 2021 (09:59:01 CET)
We consider the developed turbulence of capillary waves on shallow water. Analytic theory shows that an isotropic cascade spectrum is unstable with the respect to small angular perturbations, in particular, to spontaneous breakdown of the reflection symmetry and generation of nonzero momentum. By computer modeling we show that indeed a random pumping, generating on average zero momentum, produces turbulence with a nonzero total momentum. A strongly anisotropic large-scale pumping produces turbulence whose degree of anisotropy decreases along a cascade. It tends to saturation in the inertial interval and then further decreases in the dissipation interval. Surprisingly, neither the direction of the total momentum nor the direction of the compensated spectrum anisotropy is locked by our square box preferred directions (side or diagonal) but fluctuate.
ARTICLE | doi:10.20944/preprints202307.1659.v1
Subject: Engineering, Civil Engineering Keywords: acid gas injection (AGI); saline aquifers; capillary pressure; reservoir characterization; caprock integrity; capillary pressure
Online: 25 July 2023 (07:39:38 CEST)
Approximately 2 TCF (Trillion Cubic Feet) of acid gas are projected to be injected into the Surmeh formation. The recommended injection rate is 180 MMSCFD (Million standard cubic feet per day), based on acid gas content and gas in place of the source of injection. The tight nature of the Surmeh formation limits injectivity, with a maximum achievable rate of 7 MMSCFD for permeability of 1 mD (millidarcy). However, higher porosity (12%) and permeability of 100 mD enable more efficient injection without fracturing the formation. This study provides valuable insights into the feasibility of AGI in saline aquifers, emphasizing reservoir characterization, geomechanics, caprock integrity, and rock properties. The findings contribute to the implementation of environmentally sustainable acid gas disposal at offshore reservoirs.
Subject: Biology And Life Sciences, Aging Keywords: astaxanthin; antioxidant; skin; ultraviolet; photoaging; capillary
Online: 20 January 2020 (09:55:03 CET)
Abstract: Ultraviolet (UV) induces skin photoaging, which is characterized by thickening, wrinkling, pigmentation, and dryness. Astaxanthin, a ketocarotenoid from Haematococcus pluvialis, has been extensively studied with respect to its possible effect on skin health as well as UV protection. In addition, astaxanthin attenuates increases in the generation of reactive oxygen species (ROS) and capillary regression of skeletal muscle. In the present study, we investigated whether astaxanthin would protect UV-induced photoaging and capillary regression in the skin of HR-1 hairless mice. UV induces wrinkle formation, thickness and capillary regression in dermis of hairless mice and the administration of astaxanthin decreased the UV-induced wrinkle formation, skin thickness, and increase in collagen fibers in skin. Astaxanthin supplementation also inhibited the levels of ROS generation and attenuated the decreases in wrinkle formation, thickness and capillary number in the skin. We also found an inverse correlation between wrinkling and capillary number, and the photoaging associated with capillary regression in skin. These results suggest that astaxanthin can protect against photoaging caused by ultraviolet irradiation and the effects of astaxanthin in photoaging inhibition may be associated with the protection of capillary regression in skin.
ARTICLE | doi:10.20944/preprints202310.0298.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: Polymer; Multiscale; Fluid dynamics; Viscoelastic; Capillary thinning
Online: 6 October 2023 (05:52:22 CEST)
Modeling the flow of polymer solutions requires knowledge at various length and time scales. The macroscopic behavior is described by the overall velocity, pressure and stress. The polymeric contribution to the stress requires knowledge of the evolution of polymer chains. In this work, we use a microscopic model, the finitely extensible nonlinear elastic (FENE) model, to capture the polymer behavior. The benefit of microscopic models is they remain faithful to the polymer dynamics without information loss via averaging. The downside is the computational cost needed to solve the thousands to millions of differential equations describing the microstructure. We thus describe a multiscale flow solver that utilizes GPUs for massively parallel, efficient simulations. We compare and contrast the microscopic model with its macroscopic counterpart under various flow conditions. In particular, significant differences are observed under nonlinear flow conditions, where the polymers become highly stretched and oriented.
REVIEW | doi:10.20944/preprints202309.0567.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Pyogenic granuloma; Hyperplastic lesion; Lobulated capillary hemangioma.
Online: 8 September 2023 (09:48:56 CEST)
Oral pyogenic granuloma (PG) is generally a solitary benign connective tissue proliferation of unknown etiology. It is the most common type of oral inflammatory hyperplasia histologically characterized by proliferation of granulation tissue with inflammatory infiltrates and high angiogenic capacity. Vascular neoformations of different diameters are usually present. Due to their structural characteristics, tendency to bleed, and rapid and alarming growth rate, these neoformations may have serious consequences. Sometimes, it is complex to make an accurate diagnosis. Therefore, adequate management and treatment are based on the characteristics and systemic conditions of each patient. This review was carried out to provide an overview of the factors involved in, or attributed to the etiopathogenesis of oral PG. It describes the different forms of presentation and clinical evolution, as well as the most frequent signs and symptoms that characterize this disease, while incorporating recent radiographic and microscopic findings. In addition, it describes the different modalities for the management of oral pyogenic granuloma depending on the particular characteristics of each patient.
ARTICLE | doi:10.20944/preprints202306.0649.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: monocyte, VCAM-1, microsphere, capillary vessel, microemboli
Online: 8 June 2023 (14:02:33 CEST)
The restriction of normal blood flow is the cause of many diseases including stroke and coronary artery diseases. To study the consequences of vessel blockade, previous models mainly focused on major arteries and have been well studied. However, the sequela from interruption of capillary vessels by microemboli was less well characterized. In this study, we exploited polystyrene microspheres as a mimicry of microemboli and found that microspheres of this size can be trapped in capillary vessels of all organs without causing apparent acute morbidities of the host. Interestingly, we accidentally found significantly increased recruitment of monocyte to the brain vasculature expressing low levels of Ly6C expression, but not to other organs. Further study revealed the spleen is the major origin of the recruited monocyte. Most importantly, VCAM-1 which is constitutively expressed on mouse brain vasculature orchestrates the recruitment of monocyte. Blockade of VCAM-1 in mice can substantially reduce monocyte recruitment. Interestingly, monocytes get activated through TNF- signaling which likely happens in the spleen instead of the brain. Collectively, we found a unique monocyte recruitment strategy in the brain comparing to other orangs, in response to capillary blockade induced by polystyrene microspheres.
Subject: Physical Sciences, Acoustics Keywords: capillary; microfluidic device; single-molecule recycling; maximum likelihood
Online: 26 May 2021 (10:50:13 CEST)
Microfluidic devices have been extensively investigated in recent years in fields including ligand-binding analysis, chromatographic separation, molecular dynamics, and DNA sequencing. To prolong the observation of a single molecule in aqueous buffer, the solution in a sub-micron scale channel is driven by the electric field and reversed after a fixed delay following each passage, so that the molecule passes back and forth through the laser focus and the time before irreversible photobleaching is extended. However, this practice requires complex chemical treatment to the inner surface of the channel to prevent unexpected sticking to the surface and the confined space renders features, such as a higher viscosity and lower dielectric constant, which slow the Brownian motion of the molecule compared to the bulk liquid. In this paper, we have fixed a capillary microchannel with an inner diameter of 2 microns on top of a piezo stage to recycle the molecule and collected the fluorescence by a confocal microscope. The passing times of the molecule through the laser focus are calculated by a real-time control system based on an FPGA and the commands of translation are given to the piezo stage through a feedback algorithm. We have achieved a maximum number of recycles of more than 200 and developed a maximum-likelihood estimation of the diffusivity of the molecule, which attains results of the same magnitude as previous reports. This technique simplifies the overall procedure of the single-molecule recycling and could be useful for the ligand-binding studies of biomolecules.
REVIEW | doi:10.20944/preprints201706.0130.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: membranes; polymer solution; breath-figures; ordering; capillary cluster
Online: 30 June 2017 (11:05:45 CEST)
The review is devoted to the physical, chemical and technological aspects of the breath-figures self-assembly process. Main stages of the process and the impact of the polymer architecture and physical parameters of the breath-figures self-assembly on the eventual pattern are covered. The review is focused on the hierarchy of spatial and temporal scales inherent for the breath-figures self-assembly. Multi-scale patterns arising from the process are addressed. The characteristic spatial lateral scales of patterns vary from nanometers to dozens of micrometers. The temporal scales of the process span from micro-seconds to seconds. The qualitative analysis performed in the paper demonstrates that the process is mainly governed by the interfacial phenomena, whereas the impact of inertia and gravity is negligible. Characterization and applications of polymer films manufactured with breath-figures self-assembly are discussed.
ARTICLE | doi:10.20944/preprints202011.0183.v1
Subject: Physical Sciences, Acoustics Keywords: gravity-capillary waves; ship wake; Kelvin angle, reference solutions
Online: 4 November 2020 (10:04:41 CET)
We study wave patterns of gravity-capillary waves from moving localized sources within the classic setup of the problem of ship wakes. The focus is made on the co-existence of two wave systems with opposite signatures of group velocity relative to the localized source. It leads to the problem of choice of signs for phase functions of the gravity (“slow”) and capillary (“fast”) branches of the dispersion relation: the question generally ignored when constructing phase patterns of the solutions. We detail characteristic angles of the wake patterns: (i) angle of demarcation of gravity and capillary waves – “the phase Mach” cone, (ii) angle of the minimal group velocity of gravity-capillary waves – “the group Mach” cone, (iii, iv) angles of cusps of isophases that appear after a threshold current speed. The outer cusp cone is naturally associated with the classic cone of Kelvin for pure gravity waves. The inner one results from the effect of capillarity and tends to the “group Mach” pattern at high speeds of current. Amplitudes of the wave patterns are estimated within the recently proposed approach of reference functions for the problem of propagation of packets of linear dispersive waves. The effect of shape is discussed for elliptic reference sources.
ARTICLE | doi:10.20944/preprints202007.0127.v1
Subject: Physical Sciences, Applied Physics Keywords: capillary rise; dynamics; tube radius criteria; oscillation; monotonic rising
Online: 7 July 2020 (11:13:33 CEST)
Among the best-known capillarity phenomena is a capillary rise, the understanding of which is essential in fluidics. Some capillary flows rise monotonically whereas others oscillate, but until now no criteria have been formulated for this scenario. In this paper, the Levine's capillary rise modelling is computed numerically, then the critical radius of the capillary tube is formulated by using the dimensional method and data fitting for identification of exponent index. The phase space diagram of capillary velocity versus height is obtained for the first time and shows that the phase transition from oscillating to monotonic rising happens when the phase trajectory decreases exponentially to somewhere other than the "attractor." Two general Maple codes of the problem are provided as an essential part of this paper.
ARTICLE | doi:10.20944/preprints201810.0220.v1
Subject: Medicine And Pharmacology, Clinical Medicine Keywords: RASA1; CM-AVM; capillary malformation-arteriovenous malformation; constitutional mosaicism
Online: 10 October 2018 (12:31:54 CEST)
Introduction: Capillary malformation-arteriovenous malformation (CM-AVM; MIM#608354) is caused by germline RASA1 and EPHB4 alterations. RASA1 intralesional second hits have also been reported. Constitutional mosaicism, defined as the presence of a mosaic variant in all cell types of an individual, is detected in clinical practice as mosaic variants in multiple tested samples from one individual or as mosaic variants in blood samples in a disorder affecting another cell/tissue types. Here we report RASA1 constitutional mosaicism in CM-AVM. Subjects and methods: A custom high-throughput sequencing panel was used to search for RASA1 pathogenic variants in blood samples from two unrelated patients with a clinical diagnosis of CM-AVM. An affected tissue sample from one of the patients was also analyzed. Results: Both patients showed different nonsense RASA1 variants in mosaic in blood samples and in the corresponding affected tissue sample from one of the patients. The mosaicism ranged between 7% and 21,5%. Conclusions: We report for the first time the presence of RASA1 constitutional mosaicism in CM-AVM. Constitutional mosaicism has implications for accurate molecular diagnosis and recurrence risk, and helps to explain the great phenotypic variability in CM-AVM.
ARTICLE | doi:10.20944/preprints202201.0059.v1
Subject: Environmental And Earth Sciences, Geochemistry And Petrology Keywords: microporous carbonates; multimodal porosity; primary drainage; capillary invasion; mixed wettability
Online: 6 January 2022 (10:03:11 CET)
Improved oil recovery from tight carbonate formations may provide the world with a major source of lower-rate power over several decades. Here we provide an overview of the Arab D formation in the largest oil field on earth, the Ghawar. We investigate the occurrence of microporosity of different origins and sizes using scanning electron microscopy (SEM) and pore casting techniques. Then, we present a robust calculation of the probability of invasion and oil saturation distribution in the nested micropores using mercury injection capillary pressure data available in the literature. We show that large portions of the micropores in Arab D formation would have been bypassed during primary drainage unless the invading crude oil ganglia were sufficiently long. Considering the asphaltenic nature of oil in the Ghawar, we expect the invaded portions of the pores to turn mixed-wet, thus becoming inaccessible to waterflooding until further measures are taken to modify the system’s chemistry.
ARTICLE | doi:10.20944/preprints202311.0158.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: whole blood viscosity; reference interval; shear rate; scanning capillary tube viscometer; cat
Online: 3 November 2023 (03:31:23 CET)
Whole blood viscosity, a hemorheological factor, is currently used for diagnosis, as it is correlated with various vascular diseases that are difficult to diagnose early with a general blood test. It was determined that it was necessary to set reference intervals for further studies and utilization of whole blood viscosity in cats, a representative companion animal, and this study was conducted. 50 healthy cats were recruited for the study and whole blood viscosity, complete blood count, and serum chemistry tests were performed. The reference intervals of whole blood viscosity were 15.169 to 43.684 cP at a shear rate of 1 s-1 reflecting diastole, and 3.524 to 5.544 cP at a shear rate of 300 s-1 reflecting systole. Red blood cells, hematocrit, hemoglobin, white blood cells, and neutrophils in the complete blood count, and total protein, albumin, globulin, and cholesterol in the serum chemistry were significantly correlated with whole blood viscosity. The results of this study set reference intervals of whole blood viscosity for healthy cats in a wide shear rate range that has not yet been fully established and investigated its correlation with other blood indicators.
ARTICLE | doi:10.20944/preprints202308.0050.v1
Subject: Engineering, Mechanical Engineering Keywords: Horizontal liquid layer, boiling, critical heat flux, instabilities, capillary-porous coating, void fraction.
Online: 2 August 2023 (04:30:36 CEST)
: Two-dimensional instability of a horizontal layer of boiling liquid with a finite height is experimentally studied. In this layer, “vapor columns” rose at the corners of a square rectangular grid. The symmetry of “vapor column” location on the heating surface is considered. The model considers the approach to the boiling crisis in terms of both developed nucleate boiling and transitional boiling (the Zuber problem). When dealing with developed nucleate boiling, the layer of boiling liquid is considered in calculations as an isotropic homogeneous system (foam). It is shown how the conditions on the heating surface (capillary-porous coating) affect external hydrodynamics of the liquid layer and, ultimately, the value of the critical heat flux. The calculation ratio obtained by approaching the boiling crisis with regard to developed nucleate boiling takes into account the dependence of the critical heat flux on the void fraction of the boiling liquid layer. A new solution to the boiling crisis problem is proposed when approaching the crisis from the point of transitional boiling (the Zuber problem). This new solution eliminates some shortcomings of the classical problem (in particular, the void fraction of the layer corresponds to the experiments).
ARTICLE | doi:10.20944/preprints202102.0536.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: open-pit coal mine; dewatering; groundwater level; vadose zone; moisture movement; capillary water
Online: 24 February 2021 (09:55:58 CET)
Long-term dewatering of groundwater is a necessary operation for mining safety in open-pit coal mines, while extensive dewatering might cause ecological problems due to dramatical changes of moisture movement in the soil, especially in ecological-fragile areas. This paper presents a quantitative methodology to evaluate the impact of the coal mining operation on moisture movement in the vadose zone by taking the Baorixile open-pit coal mine as an example. A long-term in-situ experiments（from 2004 to 2018), laboratory analysis and numerical modelling were conducted to analyse the mechanisms and relationship among the dropping groundwater level, the vadose-zone moistures, and the ecological responses in the grassland area. The experiment data and modelling results suggest that groundwater level dropping during open-pit mining operation has limited influence on the vadose zone, exhibiting a variation of capillary water zone within a depth of 3 m while the vadose zone and soil water zone were at least 16 m deep. The critical evaporation depth of ground water is 8 m. The long-term influence radius of groundwater dewatering is about 2.72 km during the Baorixile mining operation, and the groundwater level change mainly influences the lower part of the intermediate vadose zone and the capillary water zone below 16 m, with little influence on the moisture contents in the soil water zone where the roots of shallow vegetation grow. The results from this study provide useful insight for sustainable development of coal mining in ecological-fragile areas.
ARTICLE | doi:10.20944/preprints202210.0213.v1
Subject: Physical Sciences, Fluids And Plasmas Physics Keywords: double emulsion; core-shell droplet; microfluidics; tri-axial capillary; computational fluid dynamics; dripping regime.
Online: 14 October 2022 (13:19:39 CEST)
We investigated experimentally, analytically and numerically the formation process of double emulsion formations under dripping regime in a tri-axial co-flow capillary device. The results show that mismatches of core and shell droplets under a given flow condition can be captured both experimentally and numerically. We propose a semi-analytical model using the match ratio between the pinch-off length of the shell droplet and the product of the core growth rate and its pinch-off time. The mismatch issue can be avoided if the match ratio is lower than unity. We considered a model with the wall effect to predict the size of the matched double emulsion. The model shows slight deviations with experimental data if the Reynolds number of continuous phase is lower than 0.06, but asymptotically approaches to good agreement if the Reynolds number increases from 0.06 to 0.14. The numerical simulation generally agrees with the experiments under various flow conditions.
COMMUNICATION | doi:10.20944/preprints202006.0115.v1
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: capillary regression; COVID-19; pro-inflammatory mediators; interleukin-1 beta; tumor necrosis factor; thrombin
Online: 9 June 2020 (04:12:30 CEST)
In this brief communication, we propose the concept that capillary regression may represent a primary pathogenic process underlying COVID-19 infection, particularly in the serious and life-threatening manifestations of the disease. We suggest that the marked elevations of pro-inflammatory mediators that are observed in these seriously ill patients may directly induce capillary regression and endothelial cell (EC) loss. Recent autopsy studies are demonstrating EC loss leading to widespread microthrombi and associated tissue damage. Recent work has indicated that interleukin-1 beta (IL-1β), tumor necrosis factor-alpha (TNFα), and thrombin, individually and in combination, can potently cause capillary tube regression in experimental models in vitro and in vivo. Other pro-inflammatory mediators including interferon gamma (IFNγ), interleukin-4 (IL-4), and interleukin-13 (IL-13) were also shown to be pro-regressive and could be relevant mediators in COVID-19 patients. Interestingly, combinations of pharmacologic agents were identified that reduced capillary regression and protected capillary tube networks against these pro-inflammatory mediators. Such an approach might be an important therapeutic option going forward to treat key disease states where capillary regression plays a major underlying pathogenic role. Finally, if capillary regression is occurring in response to these pro-inflammatory mediators during COVID-19 infection, we suggest that combinations of blocking agents directed to these key pro-regressive mediators might be necessary to appropriately treat patients.
ARTICLE | doi:10.20944/preprints202307.0253.v1
Subject: Engineering, Bioengineering Keywords: Erythrocyte sedimentation rate (ESR); shear stress index; Aggregation index; Blood shear stress; Blood flow intensity; Capillary chip
Online: 5 July 2023 (08:55:46 CEST)
Blood image intensity has been used to detect erythrocyte sedimentation rate (ESR). However, it does not give an information on biophysical properties of blood sample under continuous ESR. In this study, three physical properties, including, τ0, ESRτ, and AII, are suggested to quantify mechanical variations of blood under continuous ESR. To demonstrate the proposed method, blood sample is loaded into a driving syringe. The blood flow rate is set in a periodic on–off pattern. Blood sample is then supplied into a capillary chip, and microscopic blood images are captured at specific intervals. Blood shear stress is quantified from the interface of blood stream in the coflowing channel. Both τ0 and ESRτ are then obtained by analyzing the blood shear stress. Simultaneously, the AII is evaluated by analyzing the image intensity of blood flow. According to the experimental results, the τ0 exhibits consistent trends with respect to hematocrit as well as diluent. The ESRτ and AII showed a reciprocal relationship each other. Three suggested properties represented substantial differences for suspended blood samples (i.e., hardened red blood cells, different concentration of dextran solution and fibrinogen). In conclusion, the present method can detect variations of blood sample under continuous ESR effectively.
ARTICLE | doi:10.20944/preprints202008.0157.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: tortuous pore diffusion model (TPD model); scanning probe microscopy (SPM); capillary; hollow fiber membrane; three-dimensional tortuous pore
Online: 6 August 2020 (10:49:29 CEST)
Hemoconcentration membranes used in cardiopulmonary bypass require a pore structure design with high pure water permeability, and which does not allow protein adsorption and useful protein loss. However, studies on hemoconcentration membranes have not been conducted yet. The purpose of this study was to analyze three-dimensional pore structures and protein fouling before and after blood contact with capillary membranes using the tortuous pore diffusion model and a scanning probe microscope system. We examined two commercially available capillary membranes of similar polymer composition that are successfully used in hemoconcentration clinically. Assuming the conditions of actual use in cardiopulmonary bypass, we perfused these membranes with bovine blood. Pure water permeability before and after bovine blood perfusion was measured using the dead-end filtration. The scanning probe microscopy system was used for analysis. High-resolution three-dimensional pore structures on the inner surface of the membranes were observed before blood contact. On the other hand, pore structures after blood contact could not be observed due to protein fouling. The pore diameters calculated by the tortuous pore diffusion model and scanning probe microscopy were mostly similar and could be validated reciprocally. Achievable pure water permeabilities showed no difference despite protein fouling, leading to low values of albumin SC. This is due to the mechanism that protein fouling occurs on the membrane surface, while there is little internal pore blocking. Therefore, controlling the fouling is essential for membranes in medical use. These characteristics of the hemoconcentration membranes examined in this study are suitable for clinical use.
ARTICLE | doi:10.20944/preprints202311.0712.v1
Subject: Computer Science And Mathematics, Mathematics Keywords: equilibrium figures; viscous compressible two-layer fluid; capillary forces; interface problem for the Navier – Stokes system; the Hölder spaces
Online: 10 November 2023 (13:25:43 CET)
The paper proves the existence of a family of axisymmetric equilibrium figures as solutions of a stationary problem with unknown boundaries for the Navier–Stokes equations corresponding to the slow rotation of a viscous compressible two-layer liquid mass about some axis. It is assumed that the liquids are barotropic, capillary and have different viscosities, the internal fluid being bounded by a closed surface. This interface does not intersect with the external boundary of the cloud. The proof is based on implicit function theorem and carried out in the Hölder spaces.
ARTICLE | doi:10.20944/preprints202310.1219.v1
Subject: Environmental And Earth Sciences, Soil Science Keywords: road construction; soil stabilization; soil binders; soil compressive strength; soil capillary forces; frost resistance; waste additives; industrial waste; pyrolytic wax; emulsions; soil water absorption
Online: 20 October 2023 (11:01:31 CEST)
In road construction, before applying an asphalt or concrete surface, the ground must be compacted and stabilized. There are two basic methods of soil stabilization: in situ and in a stationary node (ex-situ). The method of performing stabilization in place (in-situ) is the most frequently used method due to its convenience and lower price. The most popular type of binder for stabilization is a hydraulic binder (most often cement and various ashes). Such stabilization is performed at a depth of 10-50 cm, achieving the desired load-bearing parameters. In order to improve them, various chemical additives for stabilization are often used, such as ion exchange compounds, additives based on sulfuric acid, additives based on vinyl polymers or even organic additives using lignosulfonates. However, the use of such additives is associated with much greater costs and environmental burden, resulting in seeking for cheaper and equally effective alternatives. The win-win situation would be for instance recycling the problematic waste-based materials that on one hand are landfilled or impossible to recycle and on the other hand cause problems for the waste producers. Therefore, an interesting issue is the production of stabilization additives from various types of waste materials. As a result of the extensive testing of various waste-based materials blends with soil, the mechanical (compressive strength after 7 and 28 days) and hydraulic (capillary rise, water absorption, frost resistance) soil properties were measured. The optimization process led to obtaining additives compositions ensuring the best strengthening and sealing properties. These were for sandy soil: Pure foil (wax emulsion), Pure foil (wax emulsion) + waste sulphuric acid, RDF from waste tires (wax emulsion), Pure foil (wax emulsion) + “by-pass” waste ash + NaOHx2 and for clayey soil: Pure foil (wax emulsion) + NaOH, Pure foil (wax emulsion) + waste sulphuric acid, Tequant, Pure foil (wax emulsion).