Single Capillary Research Articles

Comparative study of erythrocyte sedimentation rate measurement between Celltac Alpha+ (MEK-1305) ESR Analyzer and standard Westergren method

Background: The Westergren method, a gold standard method for erythrocyte sedimentation rate (ESR) measurement, is one of the screening tests for routine clinical hematology that can be used as an inflammation marker. Since the results can be altered by numerous factors, new methodologies have been established to manage the possible pitfalls. Objective: This study compared erythrocyte sedimentation rate measurements obtained by the Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer with those obtained by the standard Westergren method. Materials and methods: The Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer was used to assess the performance of ESR measurement compared to the standard Westergren method. A total of 220 random EDTA whole blood samples from patients were included and analyzed in parallel using the automated analyzer and the standard Westergren method. Results: Spearman’s rank correlation coefficient (ρ = 0.916) obtained a good correlation between the two methods. In addition, the precision was good and acceptable according to the criteria, with a %CV of less than 10% in both intra-run and inter-run precision. There was no contamination between blood samples from using a single capillary probe. Moreover, Bland-Altman mean difference plot also indicated a good agreement, with a mean bias of -1.4 (95% CI: -0.8 to 2.1), an upper LOA of 7.6 (95% CI: 6.6 to 8.7) and a lower LOA = -10.5 (95% CI: -11.6 to -9.5). Conclusion: This comparative study indicated that the Celltac Alpha+ (MEK-1305) Automated Hematology and ESR analyzer is applicable within clinical routine practice along with proper measurement regulation. Even though the principles between these two methods are completely different, an acceptable interrelation was obtained due to the calibration process by Nihon Kohden corporation.

Axial emission characteristics of an ionic liquid electrospray thruster with a circular emitter

Ionic Liquid Electrospray Thrusters (ILETs) are well suited for micro-nano satellite applications due to their small size, low power consumption, and high specific impulse. However, the limited thrust of a single-emitter ILET restricts its use in space missions. To optimize the performance of ILETs and make them suitable for a wider range of space missions, we designed a Circular-emitter ILET (CILET) to convert a one-dimensional (point) emission into a two-dimensional (line) emission. The CILET can self-organize multiple Taylor cones simultaneously. The cones were photographed and the axial emission currents were measured under different voltage and pressure difference conditions with a CILET experimental system. The emission can be divided into two stable states and one unstable state based on the flow and current characteristics. The current in Stable state I increases non-linearly with the voltage, while that in Stable state II is nearly linear with respect to the voltage. The number of cones increases with the voltage in stable states, while the cones become short and crowded under high-voltage conditions. The variation law of the number of cones can be explained with the self-organization theory. The variation in the current exhibits a good correlation with the number of cones. This study demonstrates the feasibility of circular emitters and experimentally indicates that the emission current is improved by approximately two orders of magnitude compared to that of a single capillary.

Ultra-sensitive strain sensor based on Sagnac interferometer with different length panda fiber

A high-sensitivity harmonic Vernier effect (HVE) strain sensor is fabricated by cascading Sagnac interferometer (SI) and Fabry-Perot interferometer (FPI). SI is fabricated by the panda fiber (PF). PF is a typical polarization maintaining fiber (PMF) that has two pressure zones, making it particularly sensitive to strain. SI1, SI2, and SI3 are constructed using PF with lengths of 20 cm, 50 cm, and 80 cm, respectively. They have interference spectra similar to sine waves in the wavelength range of 1250 nm to 1650 nm. Research has found that the sensitivity of SI is directly proportional to the effective PF length under strain action. In addition, if the strain acts on the entire length of the PF, the strain sensitivities of SI1, SI2, and SI3 are 30.4 pm/με, 28.4 pm/με, and 30.1 pm/με, respectively, which are relatively close. Then, FPI is fabricated by splicing single mode fiber (SMF) and quartz capillary, and it is an “SMF-Capillary-SMF” sandwich structure, and the free spectral range (FSR) of FPI is approximately half of that of SI2. FPI and SI2 are cascaded to produce a first-order HVE sensor, further amplifying the strain sensitivity of SI2. The intersection point of the internal envelope based on the HVE sensor spectrum can provide accurate spectral wavelength position and drift, and the strain sensitivity of the HVE sensor reaches 293.0 pm/με, improving the strain sensitivity of SI2 by 10.3 times. The detection limit of the HVE sensor is 0.5 µε as the strain varies from 0 to 700 µε. This HVE strain sensor is relatively easy to manufacture, low-cost, linear and reliable, and can achieve high sensitivity strain measurement. It has certain application value in the field of strain measurement.

Imbibition of water into a cellulose foam: The kinetics

Cellulose foams are representative of many porous engineering solids that can absorb a large quantity of fluid such as water. Experiments are reported to give insight into water rise in cellulose foams and the underlying mechanisms. The water rise characteristic of water height h versus time t displays a distinct knee on a log-log plot; this knee separates an initial regime where h scales as t1/2 from a subsequent regime where h scales as t1/4. The rate of water rise below the knee is consistent with the Washburn law of water rise in a single dominant capillary, and the knee in the h(t) curve suggests that the Jurin height of this large capillary has been attained. Water rise in the foam above the knee of the h(t) curve is interpreted as water rise in a population of small capillaries with a wide range of radius that feed off the dominant capillary. A series of critical experiments support this interpretation, including water rise in inclined columns, and water rise from a limited reservoir of water. A simple analytical model is used to provide a physical explanation for the observations. Additionally, X-ray computer tomography is used to deduce the probability density function of the small capillaries. The experimental findings are in support of the hypothesis that water rise in the cellulose foam is driven by capillary action and not by diffusion.

"Scleroderma" and "Scleroderma-like" Capillaroscopic Pattern-Differences and Similarities.

The "scleroderma" type capillaroscopic pattern is a reference pattern in rheumatology that is a diagnostic sign for systemic sclerosis (SSc) in an appropriate clinical context and is observed in more than 90% of scleroderma patients. Similar microvascular changes, the so-called "scleroderma-like", have been described albeit in a lower proportion of patients with other rheumatic diseases, such as dermatomyositis (DM), undifferentiated connective tissue diseases (UCTD), systemic lupus erythematosus (SLE), etc. Three distinct stages of "scleroderma" pattern have been suggested by Cutolo et al., i.e., "early", "active", and "late". However, disease duration is just one of the factors that contributes to the progression of microvascular changes, and in this regard, "active" or even "late" pattern could be observed in patients with shorter disease duration. In addition, stable microvascular changes could be found for long periods in other cases. The aim of the study was to assess the presence of differentiating features between "scleroderma" pattern in SSc and "scleroderma-like" pattern in other rheumatic diseases. 684 capillaroscopic images demonstrating a "scleroderma" and "scleroderma-like" pattern have been analysed in the current retrospective cross-sectional study. 479 capillaroscopic pictures were obtained from 50 SSc patients, 105 from 7 DM patients, 38 from 10 rheumatoid arthritis (RA) patients, 36 images from 5 patients with SLE, and 26 images from 9 patients with UCTD. All capillaroscopic images used in the current analysis have fulfilled the criteria for "sclerderma/scleroderma-like" pattern, as the pathological changes in the capillaroscopic parameters have also been confirmed by quantitative measurement of capillary diameters, capillary density, and intercapillary distance. All the images have been categorized into one of the following groups, i.e., "early", "active" and "late" phases (according to the definition of Cutolo et al.), or "other" findings, the latter being specifically described as they could not be attributed to one of the other three categories. 479 capillaroscopic pictures were obtained from 50 scleroderma patients. 31 of them showed an "early", 391 an "active" phase, and 57 a "late" phase "scleroderma" type microangiopathy. In 69 images assessed as an "active" pattern, neoangiogenesis was found. In 43 out of 105 capillaroscopic pictures from DM patients, an "active" phase was detected; in 2 of the images, a "late" pattern was found, and in 60 capillaroscopic pictures, neoangiogenesis in combination with giant capillary loops was observed. Early microangiopathy was not found in this group. Among capillaroscopic images from SLE patients, "late" phase microangiopathy was not found. "Early" phase was present in 3 images, "active" phase in 29, neoangiogenesis in "active" phase in 4 pictures. Early microangiopathy was detected in 11 capillaroscopic pictures from RA patients (8 out of 9 patients), an "active" phase in 4 images (3 patients), and in 23 capillaroscopic images, neoangiogenesis with mild capillary derangement and capillary loss and single giant capillaries ("rheumatoid neoangiogenic pattern") were observed. Classic "late" type microangiopathy was not found in RA patients as well as among patients with UCTD. The predominant capillaroscopic pattern in UCTD patients was early microangiopathy (n = 23). The rest images from UCTD exhibited features of the "active" phase. In conclusion, early microangiopathy was observed in RA, SLE, and UCTD patients, but not in patients with DM. An "active" phase "scleroderma" type capillaroscopic pattern was detected in all patient groups other than SSc, i.e., DM, SLE, RA, and UCTD. "Late" phase "scleroderma" type microangiopathy was present in patients with scleroderma and DM and was not observed in SLE, RA, and UCTD. Despite the fact that in some cases, microangiopathy in scleroderma and other rheumatic diseases may be indistinguishable, the results of the current research have shown the presence of some differentiating features between "scleroderma" and "scleroderma-like" microangiopathy that might be a morphological phenomenon associated with differences in the pathogenesis and the degree of microvascular pathology in various rheumatic diseases.

Optimization of ESP performance through chemical treatment using a single capillary in the Apiay field

The future of production in the Apiay field lies in the T2 formation, although it poses significant challenges, such as high fluid encrustation and heavy crude oil production. These issues have led to strong emulsion problems and operational issues with many wells' electro-submersible pumping systems (ESPs). In response, companies have decided that all wells with ESP equipment in the T2 formation should undergo downhole treatment using capillary scale inhibitors and fluidity improvers. However, due to operational and design constraints, some wells only have one capillary, making it difficult to prioritize and decide on a single treatment. Ecopetrol and ChampionX have collaborated to develop a new flow improver that can be applied with the scale inhibitor in the same capillary without causing incompatibility or affecting product performance. This innovative solution was implemented in five wells, using 600 ppm for the flow improver, and 25 ppm for the scale inhibitor, resulting in a significant increase in crude oil production by up to 79%, USD 55.000 in cost savings in capillary system installation, 29% energy savings, and reduced emissions. This successful application is innovative and unique in Colombia, and it sets an example for other fields facing similar challenges in the couuntry, offering a promising approach to leverage heavy crude oil production and transform the future of these fields.

Real-time blood gas analysis using pH, PO2 and PCO2 multifunctional fluorescent capillary sensing system

Real-time blood gas analysis is of great significance in disease diagnosis and treatment. Here we have developed a pH, PO2 and PCO2 multifunctional fluorescent capillary sensing system. The pH, O2 and CO2 fluorescent indicators with same excitation wavelength are fixed into a single capillary tube. The sensing system possesses sensitive fluorescence response to pH, O2 and CO2, and the changes of pH, O2 and CO2 in buffer, in vitro, and in vivo can be detected simultaneously by measuring the fluorescence signals of sensor probe. The PO2, PCO2 and pH of rabbits in four disease models were assessed efficiently by the sensing system, exhibiting similar variation trend with the results by blood gas analyzer. Studies in living rabbit display the reasonable and favorable feasibility of capillary sensing system in real-time arterial blood gas analysis. Overall, the multifunctional fluorescent capillary sensing system exhibits significant potential in real-time arterial blood gas analysis and clinical application of disease diagnosis.

Experimental and Computational Investigation of Microbubble Formation in a Single Capillary Embedded T-junction Microfluidic Device.

In recent years, there has been a notable increase in the interest toward microfluidic devices for microbubble synthesis. The upsurge can be primarily attributed to the exceptional control these devices offer in terms of both the size and the size distribution of microbubbles. Among various microfluidic devices available, capillary-embedded T-junction microfluidic (CETM) devices have been extensively used for the synthesis of microbubbles. One distinguishing feature of CETM devices from conventional T-junction devices is the existence of a wall at the right-most end, which causes a backflow of the continuous phase at the mixing zone during microbubble formation. The back flow at the mixing zone can have several implications during microbubble formation. It can possibly affect the local velocity and shearing force at the mixing zone, which in turn can affect the size and production rate of the microbubbles. Therefore, in this work, we experimentally and computationally understand the process of microbubble formation in CETM devices. The process is modeled using computational fluid dynamics (CFD) with the volume-of-fluid approach, which solves the Navier-Stokes equations for both the gas and liquid phases. Three scenarios with a constant liquid velocity of 0.053 m/s with varying gas velocity and three with a constant gas velocity of 0.049 m/s at different liquid velocities were explored. Increase in the liquid and gas velocity during microbubble formation was found to enhance production rates in both experiments and simulations. Additionally, the change in microbubble size with the change in liquid velocity was found to agree closely with the findings of the simulation with a coefficient of variation of 10%. When plotted against the time required for microbubble generation, the fluctuations in the pressure showed recurrent crests and troughs throughout the microbubble formation process. The understanding of microbubble formation in CETM devices in the presence of backflow will allow improvement in size reduction of microbubbles.

ANDeS: An automated nanoliter droplet selection and collection device

The Droplet Microarray (DMA) has emerged as a tool for high-throughput biological and chemical applications by enabling miniaturization and parallelization of experimental processes. Due to its ability to hold hundreds of nanoliter droplets, the DMA enables simple screening and analysis of samples such as cells and biomolecules. However, handling of nanoliter volumes poses a challenge, as manual recovery of nanoliter volumes is not feasible, and traditional laboratory equipment is not suited to work with such low volumes, and small array formats. To tackle this challenge, we developed the Automated Nanoliter Droplet Selection device (ANDeS), a robotic system for automated collection and transfer of nanoliter samples from DMA.ANDeS can automatically collect volumes from 50 to 350 nL from the flat surface of DMA with a movement accuracy of ±30 µm using fused silica capillaries. The system can automatically collect and transfer the droplets from DMA chip into other platforms, such as microtiter plates, conical tubes or another DMA. In addition, to ensure high throughput and multiple droplet collection, the uptake of multiple droplets within a single capillary, separated by air gaps to avoid mixing of the samples within the capillary, was optimized and demonstrated.This study shows the potential of ANDeS in laboratory applications by using it for the collection and transfer of biological samples, contained in nanoliter droplets, for subsequent analysis. The experimental results demonstrate the ability of ANDeS to increase the versatility of the DMA platform by allowing for automated retrieval of nanoliter samples from DMA, which was not possible manually on the level of individual droplets. Therefore, it widens the variety of analytical techniques that can be used for the analysis of content of individual droplets and experiments performed using DMA. Thus, ANDeS opens up opportunities to expand the development of miniaturized assays in such fields as cell screening, omics analysis and combinatorial chemistry.

Local Energy Velocity of the Air-Core Modes in Hollow-Core Fibers

In this paper, we consider the behavior of the local energy flow velocity of the fundamental air-core mode at the core-cladding boundary in two types of hollow-core fibers: hollow-core fibers with a negative curvature of the core boundary and single-capillary fibers with similar geometrical parameters. It is demonstrated that the behavior of both axial and radial components of the local energy velocity of the fundamental air-core mode is completely different for these two types of hollow-core fibers. The negative curvature of the core boundary leads to an alternating behavior of the radial projection of the local energy velocity and a decrease of two orders of magnitude compared to the values of this projection for a single capillary. In our opinion, this behavior of the local energy velocity of the fundamental air-core mode is caused by a periodic set of Poynting vector vortices that appear in the cladding capillary walls.

A novel multifunctional fluorescent capillary-based sensor for simultaneous monitoring of pH, O2 and CO2

A fluorescent capillary sensor for detecting the bioanalytically and biologically relevant analytes pH, O2, and CO2 has been designed. The sensor is based on single capillary tube with 2 mm inner diameter, which is simultaneous doped with emissive O2-sensitive indicator Ru(dpp)3(PF6)2 (RuDP), pH-sensitive and CO2-sensitive indicator 8-hydroxypyrene-1, 3,6-trisulfonic acid trisodium salt (HPTS). The multifunctional sensor can be excited at the same wavelength and realize multi-parameter optical monitoring at the different sensing position. Studies in phosphate-buffered solutions display the excellent feasibility of the capillary sensor for fluorescence detection of pH, O2, and CO2. Overall, the multifunctional capillary sensor exhibits great potential in real-time blood gas analysis, and clinical application of multi-parameter biological detection.

Thermodynamics of imbibition in capillaries of double conical structures—hourglass, diamond, and sawtooth shaped capillaries

Thermodynamics of imbibition (intrusion and extrusion) in capillaries of double conical structures is theoretically studied using the classical capillary model. By extending the knowledge of the thermodynamics of a single conical capillary, not only the nature of spontaneous imbibition but that of forced imbibition under applied external pressure are clarified. Spontaneous imbibition in capillaries of double conical structure can be predicted from the Laplace pressure in a single conical capillary. To understand the forced imbibition process, the free energy landscape along the imbibition pathway is calculated. This landscape shows either a maximum or a minimum. The former acts as the energy barrier, and the latter acts as the trap for the liquid–vapor meniscus so that the imbibition process can be either abrupt with a pressure hysteresis or gradual and continuous. The landscape also predicts a completely filled, a half-filled, and a completely empty state as the thermodynamically stable state. Furthermore, it also predicts a completely filled and a half-filled state of metastable liquid, which can be prepared by the combination of the intrusion and the extrusion process. Our study could be useful for understanding various natural fluidic systems and for designing functional fluidic devices such as a diode and a switch.

Capillary non-Newtonian seepage model of unvulcanized rubber expressed by the four-parameter rheological flow

Micro-bubbles and pores in a tire, generated by the seepage process of rubber into steel cord, seriously degrade the safety of the tire in use. However, unclear seepage behavior of unvulcanized rubber while flowing into the interstice of steel cord makes it difficult to eliminate defects. Here, we studied the seepage behavior of unvulcanized rubber in a single capillary. When the four-parameter rheological flow was compared to the common shear rheological model, it was best suited to represent the rheological behavior of unvulcanized rubber because of its lowest variance. On this basis, the single capillary seepage equation of unvulcanized rubber was developed to interpret the relationship between the flow rate, process length, pressure, and pore diameter in a single capillary tube. And it was validated by the finite element analysis method with the four-parameter rheological equation as the material parameter; the accuracy of the single capillary seepage equation reached 99.95%. It lays a foundation for further exploring the seepage model under complex conditions such as variable aperture and multiple channels.

MORPHOLOGICAL CHANGES OF THE RABBIT CORNEA IN THE LATE TERMS AFTER THE SIMULATION OF A MECHANICAL NON-PENETRATING CORNEA INJURY AND ITS CORRECTION USING DECELLULARIZED XENOSTROMA

Abstract. The global incidence of vision loss is estimated at 36 million per year, and one of the fi ve leading causes is injury or disease aff ecting the cornea. In some cases, damage to the cornea requires surgical intervention using xenografts.This study aims to investigate the peculiarities of the morphological changes of the rabbit cornea in the dynamics of experimental mechanical non-penetrating corneal injury and its correction with decellularized xenocorneal stroma.Material and methods. Experiments were performed on Chinchilla rabbits in compliance with the rules of bioethics. The animals were divided into three groups: I – animals without simulated pathology, II – animals with simulated mechanical nonenetrating corneal trauma, III – animals with corneal trauma that underwent surgical correction using pig corneal stroma obtained by the decellularization method. Animals were removed from the experiment 14 and 28 days after the beginning of pathology simulation. Rabbits of the second and third groups were subjected to a concentric epithelial incision in the upper half of the cornea of both eyes under local anaesthesia, within which the anterior epithelium was removed together with the upper layer of the corneal stroma with a disposable ophthalmic scalpel. The rabbits of the third group underwent corneal injury correction by closing the defect with decellularized pig xenocorneal stroma. For histological examination, pieces of the cornea were processed according to generally accepted methods. Para ffi n sections of the cornea were stained with hematoxylin and eosin. The thickness of the anterior corneal epithelium in the central and peripheral areas of the injury, the stroma’s thickness, and the cornea’s general thickness were determined morphometrically. The normal distribution determined the reliability of the diff erence between the data according to the student’s t-test. Diff erences were considered signifi cant at p<0,05.Results. Morphometrically established, the dynamic increase in the thickness of the anterior epithelium in the marginal zones up to 103.49±5.17 μm on the 14th day of the experiment, which is 1.44 times greater (p˂0,001) compared to the norm, and the thickness of the cornea, with the maximum value in the same period, to 759.42±27.12 μm, which exceeded the intact indicator by 2.39 times (p˂0.001). On the 28th day of the experiment, under the conditions of simulation of mechanical injury at the microscopic level, the closure of the defect with an epithelium of average thickness 60.27±2.01 μm with an uneven relief of the basal surface and areas of detachment from the substantia propria was revealed. In the upper layers of the stroma, signs of maturation of young connective tissue with the presence of fi broblastic and leukocyte cells, capillaries and disordered orientation of collagen fi bers are microscopically revealed. Morphometrically, on the 28th day, the substantia propria thickness of the second group animals is signifi cantly (p˂0.001) bigger than the norm but 1.56 times less compared to the 14th day of the experiment. Microscopically and morphometrically, it was established that under the condition of using a decellularized pig cornea for the correction of mechanical corneal trauma, hyperplasia of the epithelium of the marginal areas was most pronounced on the 14th day 126.37±5.06 μm, which resulted in the closure of the defect with a well-structured epithelial regenerate 35.20±1.07 μm without areas of exfoliation. These morphometric parameters signifi cantly (p˂0.001) exceeded those of similar groups of animals in the cornea without correction. In the same term, the dominance of cells of the fi broblastic series and the absence of morphological manifestations of infl ammation were recorded in the granulation tissue. It was histologically investigated that using a decellularized pig cornea 28 days after correction ensures the restoration of the typical structure of the cornea with the approximation of morphometric indicators to the group of intact animals. In contrast to the second experimental group, where no correction was performed, the renewed anterior epithelium of the central corneal zone of the animals of the third group had a clear diff erentiation into layers, an even relief of the basal surface and a contoured Bowman’s membrane. Its thickness 54.19±2.09 μm was unreliably diff erent from the norm. During this period of the experiment, when correction was applied, mature connective tissue and single capillaries in a state of reduction were histologically detected in the stroma, while the phenomena of maturation of connective tissue components were often observed in the cornea of the animals of the second experimental group. Microscopically, in the substantia propria, bundles of collagen fi brils were oriented parallel, which is one of the factors that ensure the cornea’s transparency.Conclusions. Microscopically and morphometrically, it was established that the use of decellularized pig cornea for the correction of mechanical corneal trauma improves the dynamics of regeneration, accelerates the maturation of granulation tissue, the healing of the defect, contributes to the structuring and restoration of the corneal morphology as close to normal as possible.

Single-microvessel occlusion produces lamina-specific microvascular flow vasodynamics and signs of neurodegenerative change

Recent studies have highlighted the importance of understanding the architecture and function of microvasculature, and dysfunction of these microvessels may underlie neurodegenerative disease. Here, we utilize a high-precision ultrafast laser-induced photothrombosis (PLP) method to occlude single capillaries and then quantitatively study the effects on vasodynamics and surrounding neurons. Analysis of the microvascular architecture and hemodynamics after single-capillary occlusion reveals distinct changes upstream vs. downstream branches, which shows rapid regional flow redistribution and local downstream blood-brain barrier (BBB) leakage. Focal ischemia via capillary occlusions surrounding labeled target neurons induces dramatic and rapid lamina-specific changes in neuronal dendritic architecture. Further, we find that micro-occlusion at two different depths within the same vascular arbor results in distinct effects on flow profiles in layers 2/3 vs layer 4. The current results reveal laminar-scale regulation distinctions in microinfarct response and raise the possibility that relatively greater impacts on microvascular function contribute to cognitive decline in neurodegenerative disease.

More of the same? Voxelotor spawns a successor, but on what success does it build?

More of the same? Voxelotor spawns a successor, but on what success does it build?

PolyX beamline at SOLARIS—Concept and first white beam commissioning results

PolyX is a compact bending magnet beamline under construction at National Synchrotron Radiation Centre SOLARIS, which will be available to users in mid-2023. The beamline is focused on X-ray microimaging and microspectroscopy in the tender/hard (4–15 keV) X-ray energy range. The name PolyX comes from polycapillary X-ray optics that will be extensively used for efficient X-ray focusing and from the possibility of using polychromatic or broadband X-rays to increase the rather low flux from the SOLARIS bending magnet in the hard X-ray energy range. Polycapillary optics will provide focal spots with sizes of 8–200 μm. Single bounce ellipsoidal capillary is expected to provide a ∼2 μm focal spot size. The main experimental techniques at PolyX will be X-ray absorption and phase-contrast imaging and microtomography, micro-X-ray fluorescence imaging and micro-X-ray absorption spectroscopy. This paper presents the concept of PolyX beamline and preliminary “white” beam commissioning results.

Electrospinning spinneret: A bridge between the visible world and the invisible nanostructures

Electrospinning spinneret: A bridge between the visible world and the invisible nanostructures

The New Attempt at Modeling of the Three-Dimensional Geometry of the Epidermal Skin Layer and the Diffusion Processes of Nanomolecular Drug Carriers in Such Structures.

Nanoparticles are presently considered the efficient carriers of medicals, cosmetics, and pharmaceuticals in the human organism. There is a lot of research carried out on the delivery of these materials in a non-invasive way. Such a method is very safe in times of global illnesses and pandemics. The most frequently investigated route is the approach to delivering nano-media through the skin as the result of diffusion processes. The stratum corneum, the outermost layer of skin, is the most resistive barrier to such a form of penetration. In this work, a new model is proposed to predict nanoparticles' transport through this layer. It introduces the concept of the three-dimensional model of the stratum corneum, which allows to define the skin surface area from which diffusion occurs. This structure was replaced by the single capillary, resulting from theoretical considerations. Modeling of the diffusion process of nanoparticles as the result of Brownian motion in such a capillary was performed numerically using COMSOL Multiphysics package programs. Further, using the dimensions of such a capillary, a new model of diffusion was developed in which the parameters allow to determine the effective diffusion coefficient as a function of nanoparticle size and the viscosity of a liquid. As a result, the proposed models provide a new and efficient approach to the determination of the nano-molecules' transport phenomena through the skin layer.

Lattice Boltzmann modeling of gaseous microflow in shale nanoporous media

Gaseous microflow in nanoporous media of ultratight shale strata was reexamined. Hundreds of nanoscale pore network samples of the Wufeng and Longmaxi shale matrix were reconstructed by ultra-precise FIB-SEM experiments and the Quartet Structure Generation Set (QSGS) method. An OpenMP-based, high-performance, parallelized MRT-LBM model to predict shale gas flow in reconstructed nanoporous media was developed accordingly. The MRT-LBM model was validated against the analytical solutions, molecular dynamics simulations, and discrete velocity method. The MRT-LBM accurately predicted gaseous microflow in the continuum, slip, and early transition flow regimes. Using this solver, extensive pore-scale simulations of the gas transport in nanoscale pore networks were performed to study the effects of pore heterogeneity and slippage effects on the apparent permeability of shale gas. It has been known that gas slippage and Knudsen diffusion dramatically improve gas flow in a single capillary. Hence, permeability models based on a bundle of capillaries followed the increasing gas flow predictions. However, our modeling results revealed that gas slippage is suppressed by pore tortuosity, wall curvature, and surface roughness. The proportionality factor of the Klinkenberg model decreases with increasing tortuosity and decreasing porosity. We develop an apparent permeability model appropriate for low-porosity and large-tortuosity shale nanoporous media, with a corrected proportionality factor.