Three-dimensional Formations Research Articles

Evolution of pharmaceuticals using 3D and 4D printing

This overview examines the latest developments and applications of 3D and 4D printing in the health care and pharmaceutical field. The technique of creating a 3D object from a 3D model in the required size and shape is known as 3D printing. Whereas, 4D printing is the establishment of intricate three-dimensional formations that can change form in response to various external inputs. Applying 3D printing technology 3D printing, the healthcare industry has produced significant strides toward a patient-centred approach. The future of biomedical science and patient-centered care could be completely transformed by 3D printing with further advancements in research and development. 3D, 4D Technology used in printing is one of the most advanced industrial technologies available worldwide. The 3D and 4D printing pharmaceutical enterprises have completed the shift from centralised to distributed systems for the purpose of creating dosage forms. The goal of the study is to support the research goal of determining the degree to which patient-specific treatment is enhanced and healthcare outcomes are improved through the use of printing technologies in pharmaceuticals. Beyond this thorough analysis, the study highlights potential and problems from several angles and comparative aspects between 3D and 4D printing.

Developing Liver Microphysiological Systems for Biomedical Applications.

Microphysiological systems (MPSs), also known as organ chips, are micro-units that integrate cells with diverse physical and biochemical environmental cues. In the field of liver MPSs, cellular components have advanced from simple planar cell cultures to more sophisticated 3D formations such as spheroids and organoids. Additionally, progress in microfluidic devices, bioprinting, engineering of matrix materials, and interdisciplinary technologies have significant promise for producing MPSs with biomimetic structures and functions. This review provides a comprehensive summary of biomimetic liver MPSs including their clinical applications and future developmental potential. First, the key components of liver MPSs, including the principal cell types and engineered structures utilized for cell cultivation, are briefly introduced. Subsequently, the biomedical applications of liver MPSs, including the creation of disease models, drug absorption, distribution, metabolism, excretion, and toxicity, are discussed. Finally, the challenges encountered by MPSs are summarized, and future research directions for their development are proposed.

Double Dust Structures in Different Stratum Phases in Moderate Magnetic Fields

Three-dimensional plasma-dust formations consisting of calibrated dust particles differing in sizes and material densities are studied. The characteristic features of the structures formation in stratified glow discharge were studied, as well as their shapes and dynamics in the external magnetic fields. From several types of powders, the spatially separated double structures were obtained, which filled the dust trap, being located in different stratum phases. For each part of the structure, the average rotational velocities were obtained as functions of the magnetic field. In the range, in which the rotation mechanism depends on the particle size and the ion drag force is dominant, the rotational velocity was numerically estimated with allowance for the parameters variation along the stratum.

Hydrodynamic Performance and Wake Topology of Schooling Fish in Three-Dimensional Formations

Photo Gallery Hydrodynamic Performance and Wake Topology of Schooling Fish in Three-Dimensional Formations Yu Pan, Yu Pan Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA e-mail: yp8xd@virginia.edu Search for other works by this author on: This Site PubMed Google Scholar Haibo Dong Haibo Dong Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA e-mail: haibo.dong@virginia.edu Search for other works by this author on: This Site PubMed Google Scholar Author and Article Information Yu Pan Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA Haibo Dong Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904, USA e-mail: yp8xd@virginia.edu e-mail: haibo.dong@virginia.edu J. Fluids Eng. Jun 2023, 145(6): 060905 (1 pages) Paper No: FE-23-1066 https://doi.org/10.1115/1.4057072 Published Online: March 10, 2023 Article history Received: February 10, 2023 Revised: February 26, 2023 Accepted: February 27, 2023

Polymers of 2,5-Dihydroxybenzoic Acid Induce Formation of Spheroids in Mammalian Cells

Cells attached to a substrate and grown in two dimensions (2D) or suspended culture cannot accurately replicate intercellular interactions in tissues and organs. Spheroids, being three-dimensional (3D) formations, are more accurately reproduce the structure of organs or neoplasms. Spheroids compared to 2D cultures demonstrate an increased survival, corresponding morphology, and a hypoxic core, which is observed in native tumors in vivo. Tumor cell spheroids also represent models of the metastatic process. Therefore, spheroids are currently widely used for testing new anticancer drugs. However, obtaining and using 3D cultures can be associated with a number of difficulties, such as the need for expensive reagents and equipment, the low rate of formation of spheroids of the required size, and the occurrence of long-term changes in cell metabolism, which depend on the methods used to create spheroids. We have found that incubation of tumor and normal cells in the presence of polymers of 2,5-dihydroxybenzoic acid (2,5-DHBA) that are nontoxic to cells can induce the formation of 3D structures. Based on this, a new method for the rapid production of 3D cultures is developed and this approach does not require the use of additional equipment, expensive reagents, and does not have a long-term effect on cell homeostasis. The spheroids obtained by this method represent models of three-dimensional structures and can be used for biological studies of intercellular interactions and detection of pharmaceutical products.

MODIFICATION OF CERAMIC MEMBRANES BY PYROCARBON FROM CARBONIZED POLY(URETHANE UREA)S

Modification of tubular ceramic membranes made of clay minerals, which were obtained by slip casting (produced by the Dumansky Institute of Colloid Chemistry and Water Chemistry of the National Academy of Sciences of Ukraine) was carried out. The membranes were modified with pyrocarbon, which was obtained by carbonization of a precursor – poly(urethane urea)s. The carbonization precursor was synthesized from polyisocyanate (average functionality 2.7) and laprol grade 5003, which was introduced into the membrane by impregnation of the corresponding solutions in ethylacetate. When laprol reacts with polyisocyanate, three-dimensional polyurethane is formed. Since undried reagents were used, water entered the pores of the membrane, which reacted with the NCO groups of the polyisocyanate to form polyurea. The parallel course of these reactions leads to the formation of poly(urethane urea)s in the pores of the membrane. Carbonization was carried at 800 °C in an argon flow. The apparent density and open porosity of the membranes were determined by CCl4 uptake. After modification, the open porosity of the membrane decreased from 29.9 to 27.3 %, the apparent density increased from 1.86 to 1.87 g/cm3. The composition and structure of the membranes were studied by X-ray diffraction analysis and SEM. It is shown that the obtained modifier is pyrocarbon - the relative intensity of reflexes increases at 26,0 - 26,4 and 41,3 and 44,2° 2Θ. Pyrocarbon covers the surface of the pores with a continuous layer, and there are also three-dimensional formations of various shapes and sizes from several nm to several microns. Testing of modified membranes was carried out by water purification from direct scarlet dye and from Ca2+ of calcium chloride using the baromembrane method at a working pressure of 0.7 MPa. The unmodified membrane does not retain direct scarlet dye and Ca2+ at all. Tests of modified membranes have shown that the membranes acquire ultrafiltration properties. The retention factor (R) for direct scarlet dye is 100 % and 25 % for Ca2+.

Investigation of the Role of Vitamin C In Enhancing the Activity of Antibacterial Agents and Biofilm Formation

Resistance to antibiotics is rapidly spreading across the globe, posing a new health-care challenge for all countries. Bacterial biofilms are three-dimensional formations made up of cells encased in a matrix of polymeric, making cells resistant to the drugs and the immune system. As a result, new tactics for inhibiting the production of the EPS matrix may lead to more efficient use of already available antibiotics. The mechanism of vitamins C effect on boosting the effectiveness of several anti-bacterial drugs was investigated in this study, the target isolates were obtained from University of Mosul/ Biology department/ bacterial culture collections and evaluated qualitatively and quantitatively. The isolates involved: Staphylococcus aureus, Escherichia coli ,Klebsiella sp., Serratia marcescens and Pseudomonas aeroginosa. Antibiotic sensitivity tests and biofilm producing assay results revealed that the majority of the isolates were resistant to a range of antibiotics and had a large capacity for biofilm formation when grown on a cover glass surface. Vitamin C is an antioxidant, a scavenger of active metabolites. The Minimum Inhibitory Concentration (MIC) of Vitamin C against selected isolates had been determined, and all further experiments used concentrations below the MIC. Our results showed that Vit.C pre-treatment enhance the bactericidal effect of antibiotic and increases bacterial susceptibility to antibiotics. Using light microscopy, experiments of sub inhibitory doses of Vitamin C revealed good suppression of selected isolates biofilm development on the cover glass surface. Vitamin C can be utilized as an antibiotic adjuvant in combination with antibiotic and has effective biofilm inhibition, caused by multidrug-resistant bacteria, according to evidence.

Energy Saving of Schooling Robotic Fish in Three-Dimensional Formations

It has long been proposed that animals flying in the air and swimming in the water could extract energy from neighbour-induced flows. A large number of mechanisms have been proposed to explain whether, and if so how, animals can save energy by moving in two-dimensional (2D) formations—individuals swim in the horizontal plane. Seldom studies explore the mechanisms in three-dimensional (3D) formations—individuals swim in both horizontal and vertical planes, even though most animals perform 3D behaviour. In this letter, taking a pair of bio-inspired robotic fish as experimental physical models, we explore the energy cost of the follower when swimming close to a neighbour in 3D formations (mainly in the vertical plane). We found the cost of the follower is mainly affected by how it spatiotemporally interacts with the 3D vortices shed by the neighbour in 3D formations. A simple linear correlation was found between the spatial factor (the height difference) and temporal factor (the body phase difference) when the follower saves most energy compared to swimming alone. Preliminary flow visualisations and 3D computational fluid dynamic simulations show this is due to the structure of vortices along the span of the caudal fin's trailing edge. Our studies shed new light on the energy saving control of multiple artificial underwater robots in 3D formations.

The effects of periapical lesion healing on bone density

Operative dental procedures may promote pulpal infections, such as tooth cavity, trauma and teeth abrasion, anaerobic microorganism colonization causing total pulp necrosis, and periapical lesions that result in bone destruction in the periapical region. Periapical radiographs are important tools for identifying periapical pathologies. However, given that the imaging system shows three-dimensional formations in two dimensions, the knowledge about the actual size of the lesion and the real relationship with the anatomic structures is limited. These limitations force clinicians to choose the high resolution and current imaging methods that show all the details of the oral structures, such as conic beam computed tomography (CBCT). CBCT is a highly effective diagnostic device for early period bone lesion detection in which the gray value for bone density is measured in Hounsfield unit (HU). Other than using CBCT, bone mineral density measurement can be done to assess the healing of existing lesions. When the periapical lesion is healing, a series of formation and destruction processes follow each other. On the one hand, mediators and tissues that must be removed from the region are destroyed by host defense cells; on the other hand, cells included in the repair process provide new tissue generation and remodelling to provide the pre-disease anatomic properties in the lesion region. This review discusses recent studies using current three-dimensional imaging methods, compared with traditional methods for bone damage due to periapical lesion formation and healing after suitable treatment. This study aims to investigate the advantages and shortcomings of existing treatment and diagnosis approaches in endodontic periradicular lesion diagnosis and treatment. The findings highlight promising diagnosis and treatment tools and suggest the expansion of minimally invasive approaches to eliminate the problems in periapical lesions.
 
 How to cite this article:
 How to cite this article: Akın Tartuk G, Tekin Bulut E. The effects of periapical lesion healing on bone density. Int Dent Res 2020;10(3):90-9. https://doi.org/10.5577/intdentres.2020.vol10.no3.5
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Biotic links in the fouling community of Odessa Bay (Black Sea)

This paper reveals the character of the biotic links between the various organisms that compose the fouling community of Odessa Bay (Black Sea). The fouling community of solid substrates is formed by 62 species of invertebrates and 12 species of macrophytes. The edificator species of the community is the Black Sea mussel Mytilus galloprovincialis Lamarck, 1819. The environment-forming role of the mussel, which is represents the core of the corresponding consortia, was examined. The leading role of sessile organisms in the formation of a superorganismic structure that significantly modifies the properties of the environment was revealed. Together with the mussel, this structure is formed by the bivalve mollusc Mytilaster lineatus (Gmelin, 1791) and the barnacle crustacean Amphibalanus improvisus (Darwin, 1854). The proportion of sessile organisms accounts for 24.6% of the total number of species in the community. In this case, they significantly dominate in relative abundance and biomass (78.9% and 98.8%, respectively). The mussels during the process of growth form complexly organized druses, which are peculiar three-dimensional formations, consisting of mussels of different sizes, fastened together with a substrate by an entire network of strong byssus threads. These formations increase the level of heterogeneity of the substrate and increase the variety of available habitats for other animals. The aggregate of these druses is a kind of sedimentary trap in which particles of nutritive detritus accumulate. The availability of accessible habitats, convenient shelters and food reserves attracts various species of invertebrates to the community. Around the core of the consortia a cluster of organisms formed associated with edificator species. An important role is played by trophic links between different mobile organisms and the phyto-component of the community. The ability of the Black Sea mussel to condition the environment, creating favourable conditions for the development of other organisms, characterizes it as an autogenic ecosystem engineer. Trophic and mediopathic links between the organisms that compose the fouling community go beyond it and extend to the inhabitants of the pelagic environment.

On the Structural Similarity of Stable Forms of Spiral-Vortex Motion

On the basis of the thermodynamic approach, inferences of the stability theory, and the method of dimensional analysis, we have obtained analytical dependences defining the relations between geometric sizes and rotation frequencies in three-dimensional spiral-vortex formations. To describe the vortex structure of the swirling flow of viscous and nonviscous fluids, we propose to introduce into consideration the notion the order parameter. It has been shown that helicity as a characteristic of the measure of decrease in the symmetry of a moving medium connected with its order is not only an invariant of the vortex flow of nonviscous media, but can also be used as the order parameter for describing the geometrical similarity of spiral-vortex structures in real fluids.

A Combinatorial Approach for Developing Ring Communication Graphs for Vehicle Formations

In this paper, we study vehicle formations employing ring-structured communication strategies and propose a combinatorial approach for developing ring graphs for vehicle formations. In vehicle platoons, a ring graph is formed when each vehicle receives information from its predecessor, and the lead vehicle receives information from the last vehicle, thus forming a ring in its basic form. In such basic form, the communication distance between the first and the last vehicle increases with the platoon size, which creates implementation issues due to sensing range limitations. If one were to employ a communication protocol such as the token ring protocol, the delay in updating information and communication arises from the need for the token to travel across the entire graph. To overcome this limitation, alternative ring graphs which are formed by smaller communication distances between vehicles are proposed in this paper. For a given formation and a constraint on the maximum communication distance between any two vehicles, an algorithm to generate a ring graph is obtained by formulating the problem as an instance of the traveling salesman problem (TSP). In contrast to the vehicle platoons, generation of a ring communication graph is not straightforward for two- and three-dimensional formations; the TSP formulation allows this for both two- and three-dimensional formations with specific constraints. In addition, with ring communication structure, it is possible to devise simple ways to reconfigure the graph when vehicles are added/removed to/from the formation, which is discussed in the paper. Further, the experimental results using mobile robots for platooning and two-dimensional formations using ring graphs are shown and discussed.

Dissolution Trapping of Carbon Dioxide in Heterogeneous Aquifers.

The geologic architecture in sedimentary reservoirs affects the behavior of density-driven flow and the dispersion of CO2-rich brine. The spatial organization and connectivity of facies types play an important role. Low-permeability facies may suppress fingering and reduce vertical spreading, but may also increase transverse mixing. This is more pronounced when geologic structures create preferential flow pathways through connected facies types. We perform high-resolution simulations of three-dimensional (3D) heterogeneous formations whose connectivity cannot be represented in two-dimensional models consistent with percolation theory. This work focuses on the importance of 3D facies-based heterogeneity and connectivity on advection-diffusion transport of dissolved CO2. Because the dissolution of CO2 and the subsequent density increase of brine are the driving force for gravitational instabilities, we model the phase behavior with the accurate cubic-plus-association equation-of-state, which accounts for the self-association of polar water molecules and the cross-association between CO2 and water. Our results elucidate how the spatial organization of facies affects the dynamics of CO2 convective mixing. Scaling relations for the evolution of a global dispersion-width provide insights that can be universally applied. The results suggest that the long-term evolution and scaling of dispersion are surprisingly similar for homogeneous and (binary and multiscale) heterogeneous porous media.

ENHANCEMENT OF ELECTRICAL CONDUCTIVITY AND FILLER DISPERSION OF CARBON NANOTUBE FILLED NATURAL RUBBER COMPOSITES BY LATEX MIXING AND IN SITU SILANIZATION

ABSTRACTCarbon nanotube (CNT)-filled natural rubber (NR) composites were prepared by melt and by latex mixing methods. Also in situ functionalization of CNTs with a silane coupling agent, namely bis(triethoxysilylpropyl)tetrasulfide (TESPT), was done to improve the filler–rubber interactions between CNT surfaces and rubber molecules. The grafting of TESPT molecules on CNT surfaces was confirmed by attenuated total reflection (ATR)–Fourier transform infrared (FTIR) spectroscopy and by the improvement of composite properties. Tensile properties were determined to assess the reinforcement efficiency of the CNTs in the composites. Also, electrical conductivity of the composites was measured to assess the formation of CNT networks (or connected conductive CNT pathways) in the rubber matrix. The results indicate that the composites prepared by latex mixing, in particular with the TESPT, had better tensile properties and electrical conductivities than the composites made by melt mixing. The lowest percolation threshold concentration, about 0.55 phr of CNTs, was observed in the latex–CNT composites, and three-dimensional network formations of CNTs in the rubber matrix were found with added TESPT, used by in situ functionalization. The improvement of filler–rubber interactions with the addition of TESPT was also examined by temperature scanning stress relaxation measurements, revealing the relaxation modulus, the relaxation spectrum, and an estimate of the cross-link density.

Discrete fracture model for coupled flow and geomechanics

We present a fully implicit formulation of coupled flow and geomechanics for fractured three-dimensional subsurface formations. The Reservoir Characterization Model (RCM) consists of a computational grid, in which the fractures are represented explicitly. The Discrete Fracture Model (DFM) has been widely used to model the flow and transport in natural geological porous formations. Here, we extend the DFM approach to model deformation. The flow equations are discretized using a finite-volume method, and the poroelasticity equations are discretized using a Galerkin finite-element approximation. The two discretizations—flow and mechanics—share the same three-dimensional unstructured grid. The mechanical behavior of the fractures is modeled as a contact problem between two computational planes. The set of fully coupled nonlinear equations is solved implicitly. The implementation is validated for two problems with analytical solutions. The methodology is then applied to a shale-gas production scenario where a synthetic reservoir with 100 natural fractures is produced using a hydraulically fractured horizontal well.

Local structural properties of dusty plasma systems based on an analysis of three- and four-particle correlations

We present the results of an experimental study of many-body correlations (three- and four-) of three-dimensional dust formations, confined in the plasma of high-frequency capacitive discharge. The analysis of dusty plasma system, based on the reconstruction of three coordinates of dust particles using the method of binocular observation, has been made for the first time. The obtained experimental results are compared with the superposition approximation.

Three-dimensional circular formations via set stabilization

The paper addresses distributed stabilization of a class of circular formations for steered kinematic particles in three-dimensional Euclidean space. Information exchange between the particles is modeled by a bidirectional graph which is assumed to have a spanning tree. Distributed control design is based on a hierarchical approach that relies on set stabilization and a reduction principle for asymptotic stability of closed sets. The approach allows to solve for different formation specifications in a decoupled manner.

Advective Transport Through Three-Dimensional Anisotropic Formations of Bimodal Hydraulic Conductivity

Transport of a non-reactive solute in anisotropic bimodal porous formations is investigated through the evaluation of the breakthrough curve. The hydraulic conductivity $$K$$ structure is modelled as an ensemble of anisotropic and non-overlapping inclusions, with given hydraulic conductivity $$K_{i}$$ , randomly placed in an homogeneous matrix with hydraulic conductivity $$K_{0}$$ . The conductivity contrast $$\kappa =K_{i}/K_{0}$$ between the inclusions and the matrix represents the main source of heterogeneity. The resulting $$K$$ structure is a theoretical representation of natural porous formations where inclusions and matrix play the role of two distinct hydrofacies. Semi-analytical solutions for flow and transport are carried out in both 3D and 2D domains following a Lagrangian approach by adopting the dilute limit approximation. The procedure, formally valid for media with low inclusions–matrix relative volume fraction, is extended to dense media by a simplified formulation of the self-consistent approach. Natural porous formations are intrinsically anisotropic due to the depositional process; hence, particular emphasis is addressed to the quantification of the effects of the anisotropy on solute transport. The solution of our physically based model depends on three structural parameters: the hydraulic conductivity contrast $$\kappa $$ , the relative volume fraction $$n$$ , and the statistical anisotropy ratio $$e$$ . The procedure allows for the physical representation of high-velocity channels and stagnation zones, which can be encountered in bimodal media, and it is particular advantageous for a quick estimation of the solute breakthrough curve. Our analysis shows different transport dynamics, as function of the conductivity contrast $$\kappa =K_{i}/K_{0}$$ , leading to fast preferential flow ( $$\kappa >1$$ ) or mass retention ( $$\kappa <1$$ ), as a consequence of the lack of symmetry of the flow and transport parameters (velocity and travel time residuals). High dispersion is typically found when $$\kappa <1$$ , i.e. for low conductive inclusions, where the latter typically trap the solute particles, determining large travel times. Conversely, when $$\kappa >1$$ flow in the inclusions is constrained by the outer flow, limiting the solute velocity inside the inclusions, which results is a rather limited dispersion. Anisotropy typically enhances the solute spreading for $$\kappa <1,$$ as a consequence of the slower velocity predicted for more anisotropic inclusions, while its impact on formations with high $$\kappa $$ is rather limited.

Natural insect and plant micro-/nanostructsured surfaces: an excellent selection of valuable templates with superhydrophobic and self-cleaning properties.

Insects and plants are two types of organisms that are widely separated on the evolutionary tree; for example, plants are mostly phototrophic organisms whilst insects are heterotrophic organisms. In order to cope with environmental stresses, their surfaces have developed cuticular layers that consist of highly sophisticated structures. These structures serve a number of purposes, and impart useful properties to these surfaces. These two groups of organisms are the only ones identified thus far that possess truly superhydrophobic and self-cleaning properties. These properties result from their micro- and nano-scale structures, comprised of three-dimensional wax formations. This review analyzes the surface topologies and surface chemistry of insects and plants in order to identify the features common to both organisms, with particular reference to their superhydrophobic and self-cleaning properties. This information will be valuable when determining the potential application of these surfaces in the design and manufacture of superhydrophobic and self-cleaning devices, including those that can be used in the manufacture of biomedical implants.

Analytical solutions for flow of horizontal well in compressible, three-dimensional unconsolidated formations

A novel mathematical model for single-phase fluid flow from unconsolidated formations to a horizontal well with the consideration of stress-sensitive permeability is presented. The model assumes the formation permeability is an exponential function of the pore pressure. Using a perturbation technique, the model is solved for either constant pressure or constant flux or infinite lateral boundary conditions with closed top and bottom boundaries. Through Laplace transformation, finite Fourier transformation and numerical inversion methods, the solutions are obtained and the pressure response curves are analyzed. The agreement between the analytical solutions in this paper and the numerical results from commercial software (Saphir) is excellent, which manifests the accuracy of the results derived in this paper.