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1
Gounley, John, e Yan Peng. "Shape Recovery of Elastic Capsules from Shear Flow Induced Deformation". Communications in Computational Physics 16, n. 1 (luglio 2014): 56–74. http://dx.doi.org/10.4208/cicp.220513.151113a.
Testo completoAbstract (sommario):
AbstractRed blood cells undergo substantial shape changes in vivo. Modeled as a viscoelastic capsule, their deformation and equilibrium behavior has been extensively studied. We consider how 2D capsules recover their shape, after having been deformed to ‘equilibrium’ behavior by shear flow. The fluid-structure interaction is modeled using the multiple-relaxation time lattice Boltzmann (LBM) and immersed boundary (IBM) methods. Characterizing the capsule’s shape recovery with the Taylor deformation parameter, we find that a single exponential decay model suffices to describe the recovery of a circular capsule. However, for biconcave capsules whose equilibrium behaviors are tank-treading and tumbling, we posit a two-part recovery, modeled with a pair of exponential decay functions. We consider how these two recovery modes depend on the capsule’s shear elasticity, membrane viscosity, and bending stiffness, along with the ratio of the viscosity of the fluid inside the capsule to the ambient fluid viscosity. We find that the initial recovery mode for a tank-treading biconcave capsule is dominated by shear elasticity and membrane viscosity. On the other hand, the latter recovery mode for both tumbling and tank-treading capsules, depends clearly on shear elasticity, bending stiffness, and the viscosity ratio.
2
Pervaiz, Fahad, Sana Ali Zahra, Fariah Qaiser, Syeda Komal Fatima e Rabbia Mazhar Khan. "Characterization and Evaluation of Capsules and Study of QC tests for Capsules". Global Pharmaceutical Sciences Review III, n. I (30 dicembre 2018): 7–18. http://dx.doi.org/10.31703/gpsr.2018(iii-i).02.
Testo completoAbstract (sommario):
Using the capsule as a dosage form dates back to the early pharmacy days; from those days, the capsule preparation process is greatly evolved in order to meet the current needs of patients and the pharmaceutical industry. Currently, all pharmaceutical industries are making a dynamic change in the specifications of particular dosage forms such as capsules. It has become more difficult to obtain the higher valued drug product from the dosage form, along with the potential for improved delivery that can improve clinical outcomes. In addition, the capsules have played a significant role in drug development because of the hand filling or the production of semiautomatic capsular formulations, which have fewer requirements, and can be developed easily. The article will discuss different tests like Universal tests and specific tests, particularly for capsules, performed prior to the release of the batch to ensure efficacy and safety.
3
Rump, Adrian, Marie-Luise Kromrey, Eberhard Scheuch, Vincent Jannin, Lara Rehenbrock, Mladen Vassilev Tzvetkov, Werner Weitschies e Michael Grimm. "In Vivo Evaluation of a Gastro-Resistant HPMC-Based “Next Generation Enteric” Capsule". Pharmaceutics 14, n. 10 (21 settembre 2022): 1999. http://dx.doi.org/10.3390/pharmaceutics14101999.
Testo completoAbstract (sommario):
Many orally dosed APIs are bioavailable only when formulated as an enteric dosage form to protect them from the harsh environment of the stomach. However, an enteric formulation is often accompanied with a higher development effort in the first place and the potential degradation of fragile APIs during the coating process. Ready-to-use enteric hard capsules would be an easily available alternative to test and develop APIs in enteric formulations, while decreasing the time and cost of process development. In this regard, Lonza Capsugel® Next Generation Enteric capsules offer a promising approach as functional capsules. The in vivo performance of these capsules was observed with two independent techniques (MRI and caffeine in saliva) in eight human volunteers. No disintegration or content release in the stomach was observed, even after highly variable individual gastric residence times (range 7.5 to 82.5 min), indicating the reliable enteric properties of these capsules. Seven capsules disintegrated in the distal part of the small intestine; one capsule showed an uncommonly fast intestinal transit (15 min) and disintegrated in the colon. The results for this latter capsule by MRI and caffeine appearance differed dramatically, whereas for all other capsules disintegrating in the small intestine, the results were very comparable, which highlights the necessity for reliable and complementary measurement methods. No correlation could be found between the gastric residence time and disintegration after gastric emptying, which confirms the robust enteric formulation of those capsules.
4
Gupta, Shallini, Kanika Khajuria, Niraj Kumar e Vijay Khajuria. "Evaluation of capsule labelling for its wall contents as gelatin or non gelatin". International Journal of Basic & Clinical Pharmacology 7, n. 7 (22 giugno 2018): 1387. http://dx.doi.org/10.18203/2319-2003.ijbcp20182687.
Testo completoAbstract (sommario):
Background: Capsules are the most commonly used solid drug dosage form and are made up of gelatin or non gelatin. Currently the gelatin based capsules drug formulations are more used. However, current issue of vegetarian and non vegetarian capsules has come up due to recent Indian government initiative to promote vegetarian capsules.Methods: There were 100 capsule dosage forms were examined for the gelatin or HPMC wall contents and nature of medicine contained in capsules, whether ayurvedic or allopathic.Results: Out of 100 capsules studied 55 had gelatin wall base while 25 had HPMC and 20 capsule labels did not mention the nature of capsule wall constituent. Out of 55 gelatin capsules 30 were of allopathic while 25 capsules were of ayurvedic medicines. Among HPMC, 15 were ayurvedic while 10 allopathic. 20 capsules had no mention of its constituent and among these non labelled capsule formulations had 11 from ayurvedic and 9 from allopathic medicines.Conclusions: The current study revealed that gelatin capsules forms bulk in Indian market. Even the gelatin capsules contained ayurvedic medicines while 10% of HPMC capsules contained allopathic medicines. Non labelled capsules formed 20% of total capsules. These findings suggest wider scope for promotion of HPMC based capsules.
5
Rump, Adrian, Franziska N. Weiss, Louisa Schulz, Marie-Luise Kromrey, Eberhard Scheuch, Mladen V. Tzvetkov, Tyler White et al. "The Effect of Capsule-in-Capsule Combinations on In Vivo Disintegration in Human Volunteers: A Combined Imaging and Salivary Tracer Study". Pharmaceutics 13, n. 12 (25 novembre 2021): 2002. http://dx.doi.org/10.3390/pharmaceutics13122002.
Testo completoAbstract (sommario):
Controlling the time point and site of the release of active ingredients within the gastrointestinal tract after administration of oral delivery systems is still a challenge. In this study, the effect of the combination of small capsules (size 3) and large capsules (size 00) on the disintegration site and time was investigated using magnetic resonance imaging (MRI) in combination with a salivary tracer technique. As capsule shells, Vcaps® HPMC capsules, Vcaps® Plus HPMC capsules, gelatin and DRcaps® designed release capsules were used. The three HPMC-based capsules (Vcaps®, Vcaps® Plus and DRcaps® capsules) were tested as single capsules; furthermore, seven DUOCAP® capsule-in-capsule combinations were tested in a 10-way crossover open-label study in six healthy volunteers. The capsules contained iron oxide and hibiscus tea powder as tracers for visualization in MRI, and two different caffeine species (natural caffeine and 13C3) to follow caffeine release and absorption as measured by salivary levels. Results showed that the timing and location of disintegration in the gastrointestinal tract can be measured and differed when using different combinations of capsule shells. Increased variability among the six subjects was observed in most of the capsule combinations. The lowest variability in gastrointestinal localization of disintegration was observed for the DUOCAP® capsule-in-capsule configuration using a DRcaps® designed release capsule within a DRcaps® designed release outer capsule. In this combination, the inner DRcaps® designed release capsule always opened reliably after reaching the ileum. Thus, this combination enables targeted delivery to the distal small intestine. Among the single capsules tested, Vcaps® Plus HPMC capsules showed the fastest and most consistent disintegration.
6
Koolivand, Abdollah, e Panagiotis Dimitrakopoulos. "Motion of an Elastic Capsule in a Trapezoidal Microchannel under Stokes Flow Conditions". Polymers 12, n. 5 (17 maggio 2020): 1144. http://dx.doi.org/10.3390/polym12051144.
Testo completoAbstract (sommario):
Even though the research interest in the last decades has been mainly focused on the capsule dynamics in cylindrical or rectangular ducts, channels with asymmetric cross-sections may also be desirable especially for capsule migration and sorting. Therefore, in the present study we investigate computationally the motion of an elastic spherical capsule in an isosceles trapezoidal microchannel at low and moderate flow rates under the Stokes regime. The steady-state capsule location is quite close to the location where the single-phase velocity of the surrounding fluid is maximized. Owing to the asymmetry of the trapezoidal channel, the capsule’s steady-state shape is asymmetric while its membrane slowly tank-treads. In addition, our investigation reveals that tall trapezoidal channels with low base ratios produce significant off-center migration for large capsules compared to that for smaller capsules for a given channel length. Thus, we propose a microdevice for the sorting of artificial and physiological capsules based on their size, by utilizing tall trapezoidal microchannels with low base ratios. The proposed sorting microdevice can be readily produced via glass fabrication or as a microfluidic device via micromilling, while the required flow conditions do not cause membrane rupture.
7
Jann, Klaus, e Barbara Jann. "Capsules of Escherichia coli, expression and biological significance". Canadian Journal of Microbiology 38, n. 7 (1 luglio 1992): 705–10. http://dx.doi.org/10.1139/m92-116.
Testo completoAbstract (sommario):
Escherichia coli may cause intestinal or extraintestinal infections. Generally, extraintestinal E. coli are encapsulated. The capsules are important virulence determinants, which enable the pathogenic bacteria to evade or counteract the unspecific host defense during the early (preimmune) phase of infection. They interfere with the action of complement and phagocytes. This effect is generally transient and overcome by capsule-specific antibodies in the immune phase of the host defense. In some cases, capsules are not or only poorly immunogenic, as a result of structural relationship or identity with host material. Strains with such capsules (e.g., K1 or K5) are very virulent. Bacterial capsules consist of acidic polysaccharides, which are made up from oligosaccharide repeating units. The capsules of E. coli are divided into two groups, which differ in chemistry, biochemistry, and genetic organization. All capsular polysaccharides are chromosomally determined: those of group I close to his and those of group II close to serA. The biosynthesis and surface expression have been extensively studied with representatives of group II capsular polysaccharides. It could be shown that their biosynthesis is directed from a gene block that determines the synthesis of the polysaccharide, its translocation across the cytoplasmic membrane, as well as its surface expression in a coordinate process. The chemical nature of group II capsular polysaccharides, as well as the mechanism(s) of their biosynthesis and expression, is presented. Key words: Escherichia coli, capsular polysaccharides, structure, genetics, biology.
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Cordero, Radames J. B., Bruno Pontes, Allan J. Guimarães, Luis R. Martinez, Johanna Rivera, Bettina C. Fries, Leonardo Nimrichter, Marcio L. Rodrigues, Nathan B. Viana e Arturo Casadevall. "Chronological Aging Is Associated with Biophysical and Chemical Changes in the Capsule of Cryptococcus neoformans". Infection and Immunity 79, n. 12 (3 ottobre 2011): 4990–5000. http://dx.doi.org/10.1128/iai.05789-11.
Testo completoAbstract (sommario):
ABSTRACTDoes the age of a microbial cell affect its virulence factors? To our knowledge, this question has not been addressed previously, but the answer is of great relevance for chronic infections where microbial cells persist and age in hosts.Cryptococcus neoformansis an encapsulated human-pathogenic fungus notorious for causing chronic infections where cells of variable age persist in tissue. The major virulence factor forC. neoformansis a polysaccharide (PS) capsule. To understand how chronological age could impact the cryptococcal capsule properties, we compared the elastic properties, permeabilities, zeta potentials, and glycosidic compositions of capsules from young and old cells and found significant differences in all parameters measured. Changes in capsular properties were paralleled by changes in PS molecular mass and density, as well as modified antigenic density and antiphagocytic properties. Remarkably, chronological aging under stationary-phase growth conditions was associated with the expression of α-1,3-glucans in the capsule, indicating a new structural capsular component. Our results establish that cryptococcal capsules are highly dynamic structures that change dramatically with chronological aging under prolonged stationary-phase growth conditions. Changes associated with cellular aging in chronic infections could contribute to the remarkable capacity of this fungus to persist in tissues by generating phenotypically and antigenically different capsules.
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Choi, Yun-Wang, Cheol-Gyu Kim, Eun-Joon Nam e Sung-Rok Oh. "An Experimental Study on the Healing Performance of Complex Capsules Using Multiphase Inorganic Materials for Crack Self-Healing of Cement Mortars". Materials 15, n. 24 (9 dicembre 2022): 8819. http://dx.doi.org/10.3390/ma15248819.
Testo completoAbstract (sommario):
Recently, a self-healing technique capable of repairing cracks in structures has emerged. Among various self-healing technologies, self-healing capsules can be largely classified into two types, depending on the phase of the core material: solid capsules, in which the core material is a powder; and microcapsules, in which the core material is a liquid. Solid capsules and microcapsules have different mechanisms, and their capsule sizes are also distinctly different. This suggests that each has advantages and disadvantages. Most of the studies known to date have utilized single capsules. However, if one uses a mixture of the two types of capsules, it is possible to highlight the strengths of each capsule and compensate for the weaknesses. Therefore, in this study, the first research on complex capsules that mixed solid capsules and microcapsules was attempted. As a result of the experiment, the complex capsule slightly reduced the fluidity of the mortar, but the effect was not significant. Moreover, the complex capsule tended to reduce the compressive strength of the mortar. In particular, it was found that the effect of solid capsules on the reduction in compressive strength among complex capsules was greater than that of microcapsules. Conversely, the healing performance increased when the ratio of solid capsules in the complex capsules was large.
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Marshall, Joanna M., e John S. Gunn. "The O-Antigen Capsule of Salmonella enterica Serovar Typhimurium Facilitates Serum Resistance and Surface Expression of FliC". Infection and Immunity 83, n. 10 (20 luglio 2015): 3946–59. http://dx.doi.org/10.1128/iai.00634-15.
Testo completoAbstract (sommario):
Group IV polysaccharide capsules are common in enteric bacteria and have more recently been described in nontyphoidalSalmonellaspecies. Such capsules are known as O-antigen (O-Ag) capsules, due to their high degree of similarity to the O-Ag of the lipopolysaccharide (LPSO-Ag). Capsular polysaccharides are known virulence factors of many bacterial pathogens, facilitating evasion of immune recognition and systemic dissemination within the host. Previous studies on the O-Ag capsule of salmonellae have focused primarily on its role in bacterial surface attachment and chronic infection; however, the potential effects of the O-Ag capsule on acute pathogenesis have yet to be investigated. While much of thein vivoinnate immune resistance ofSalmonella entericaserovar Typhimurium is attributed to the high-molecular-weight LPS, we hypothesized that the O-Ag capsule may enhance this resistance by diminishing surface expression of pathogen-associated molecular patterns, such as flagella, and increasing resistance to host immune molecules. To test this hypothesis, O-Ag capsule-deficient mutants were constructed, and the loss of O-Ag capsular surface expression was confirmed through microscopy and immunoblotting. Loss of O-Ag capsule production did not alter bacterial growth or production of LPS. Western blot analysis and confocal microscopy revealed that O-Ag capsule-deficient mutants demonstrate reduced resistance to killing by human serum. Furthermore, O-Ag capsule-deficient mutants produced exclusively phase I flagellin (FliC). Although O-Ag capsule-deficient mutants did not exhibit reduced virulence in a murine model of acute infection,in vitroresults indicate that the O-Ag capsule may function to modify the antigenic nature of the bacterial surface, warranting additional investigation of a potential role of the structure in pathogenesis.
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O'Riordan, Katherine, e Jean C. Lee. "Staphylococcus aureus Capsular Polysaccharides". Clinical Microbiology Reviews 17, n. 1 (gennaio 2004): 218–34. http://dx.doi.org/10.1128/cmr.17.1.218-234.2004.
Testo completoAbstract (sommario):
SUMMARY Serotype 5 and 8 capsular polysaccharides predominate among clinical isolates of Staphylococcus aureus. The results of experiments in animal models of infection have revealed that staphylococcal capsules are important in the pathogenesis of S. aureus infections. The capsule enhances staphylococcal virulence by impeding phagocytosis, resulting in bacterial persistence in the bloodstream of infected hosts. S. aureus capsules also promote abscess formation in rats. Although the capsule has been shown to modulate S. aureus adherence to endothelial surfaces in vitro, animal studies suggest that it also promotes bacterial colonization and persistence on mucosal surfaces. S. aureus capsular antigens are surface associated, limited in antigenic specificity, and highly conserved among clinical isolates. With the emergence of vancomycin-resistant S. aureus in the United States in 2002, new strategies are needed to combat staphylococcal infections. Purified serotype 5 and 8 capsular polysaccharides offer promise as target antigens for a vaccine to prevent staphylococcal infections, although the inclusion of other antigens is likely to be essential in the development of an effective S. aureus vaccine. The genetics and mechanisms of capsule biosynthesis are complex, and much work remains to enhance our understanding of capsule biosynthesis and its regulation.
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Babita Himmatrao More, Vaibahavi Pradeep Shirke, Aditya Sanjeev Bhambure e Rupali Rajesh Tasgaonkar. "Duocapsule and alternative shell material to gelatin: Advancement in capsule formulation". World Journal of Biology Pharmacy and Health Sciences 13, n. 2 (28 febbraio 2023): 221–27. http://dx.doi.org/10.30574/wjbphs.2023.13.2.0076.
Testo completoAbstract (sommario):
Owing to broad advantages like self-medication, unit dosage form, and patient compliance, cost effective, limited interaction with the excipients and possibility of mask the unpleasant taste, capsules are the most extensively recognized conventional solid dosage form after Tablet. In the world of Novel drug delivery system to overcome the disadvantages of conventional delivery system modifications are made in the capsule to develop a product of higher selectivity for medical treatment like the capsules that facilitates the controlled drug delivery, sustained and targeted release profiles with its own benefits as conventional dosage form. The advancement in capsules has led to the formation of different types of capsule formulations such as tablets in capsules, pellets in capsule and the capsule in another capsule, liquid in capsule products and pellets in capsule formulations. This article aims to highlights the advancement in the capsule system, particularly Duocapsules and capsules with capsule shell prepared with alternative shell material to gelatin. The Duo capsule is also called as capsule in capsule formulation as it contains two capsules one with the bigger size containing the smaller sized capsule inside it with different or same formulations in various forms such as liquids, solids, powders, tablets, pellets etc. The article mainly focuses on the different applications, advantages, formulation consideration, and applicable drugs of duo capsules. Considering the challenges invovled in manufacturing the gelatin shell and unstability of in different climatic conditions, the present article also emphasizes on the formulation development in capsule system with alternative polymers to the gelatin like HPMC, starch and PVA copolymer capsule shells.
13
Luo, Zheng Yuan, Long He e Bo Feng Bai. "Deformation of spherical compound capsules in simple shear flow". Journal of Fluid Mechanics 775 (16 giugno 2015): 77–104. http://dx.doi.org/10.1017/jfm.2015.286.
Testo completoAbstract (sommario):
The deformation of a compound capsule (an elastic capsule with a smaller capsule inside) in simple shear flow is studied by using three-dimensional numerical simulations based on a front tracking method. The inner and outer capsules are concentric and initially spherical. Skalaket al.’s constitutive law is employed for the mechanics of both the inner and outer membranes. Our results concerning the deformation of homogeneous capsules (i.e. capsules without the inner capsules) are quantitatively in agreement with the predictions of previous numerical simulations and perturbation theories. Compared to homogeneous capsules, compound capsules exhibit smaller deformation. The deformations of both the inner and outer capsules are significantly affected by the capillary numbers of the inner and outer membranes and the volume ratio of the inner to the outer capsule. When the inner capsule is small, it presents smaller deformation than the outer capsule. However, when the inner capsule is sufficiently large, it can present larger deformation than the outer capsule, even if the inner membrane has much lower capillary number than the outer membrane. The underlying mechanisms are discussed: (i) the inner capsule is deformed by rotational flow with lower rate of strain rather than by simple shear flow that deforms the outer capsule, and thus the inner capsule exhibits smaller deformation; and (ii) when the inner and outer membranes are sufficiently close (i.e. the inner capsule is sufficiently large), the hydrodynamic interaction between the two membranes becomes significant, which is found to inhibit the deformation of the outer capsule but to promote the deformation of the inner capsule.
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Sosnoskie*, Lynn Marie, John Cardina, Sajal Sthapit, David Francis e A. Raymond Miller. "Morphological and Phenological Variation in World Collections of Velvetleaf (Abutilon theophrasti)". HortScience 39, n. 4 (luglio 2004): 753A—753. http://dx.doi.org/10.21273/hortsci.39.4.753a.
Testo completoAbstract (sommario):
Our lab characterized the growth and development of 83 velvetleaf accessions, collected from locations in Asia, India, Europe, Eastern Africa and North America, to test the hypothesis that two biotypes (“crop” and “weedy”) exist and are easily differentiated. Measurements taken to gauge morphological and phenological variability include: initial seed weight, stem height at 3, 7, and 11 weeks, leaf size at 3, 7, and 11 weeks, stem and petiole color, time to flowering, time to first capsule maturity, stem height at flowering, height to first mature capsule, basal stem diameter, number of capsules, and capsule size and color. Analyses indicate that accessions producing yellow-colored seed capsules were taller, produced fewer nodes, and were longer-lived than their brown-colored counterparts. This finding supports previous assertions that the yellow-colored varieties were originally selected for use as a fiber crop: i.e., increased stem yield resulted in longer lengths of lignified tissue. The accessions producing brown-colored capsules exhibited greater reproductive output, as measured by the number of capsules and the number of seed-containing valves per capsule, a desirable trait for weedy species. Using capsule color as an independent variable, Discriminant Analysis was able to correctly classify 96% of the observations by the remaining characters, further affirming that the yellow- and brown-capsuled accessions varied, significantly, with respect to their morphology and phenology. Velvetleaf is believed to have originated in China, where it was eventually domesticated. Early records suggest that velvetleaf, a noxious weed in modern agricultural production, was introduced to colonial America to serve as a fiber source for the burgeoning rope-making industry.
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Li, Ye, e Heng Jian Zhang. "Determinants of Entrapment of R-Phycoerythrin within Ployeletrolyte Microcapsules". Advanced Materials Research 183-185 (gennaio 2011): 1657–61. http://dx.doi.org/10.4028/www.scientific.net/amr.183-185.1657.
Testo completoAbstract (sommario):
Micrometer sized polyelectrolyte capsules have been fabricated by employing the layer-by-layer adsorption technique on charged colloidal particles with subsequent decomposition and removal of the core. Based on the permeable properties of capsules, the fluorescent proteins, R-Phycoerythrins are used to examine protein load behaviors. The loading of R-PE on capsules depends on intramolecular electrostatic attraction and intermolecular repulsion interaction. The loading rules on positively charged capsules (PSS/PAH)4and negatively charged capsules (PSS/PAH)4PSS are different, although R-PEs demonstrates the largest load capacity around isoelectric point, which is almost independent of surface charge of the capsules. In the case, driving force of encapsulation of protein into the capsule is hydrophobic mainly, while the fluorescent protein is absorbed on the shell of positively charged capsule (PSS/PAH)4. However, the R-PE was completely encapsulated into negatively charged capsules (PSS/PAH)4PSS. Therefore, compared to the positively charged capsules, negatively charged capsules is more favorable to macromolecules permeating into the capsule interior. Based on the Freundlich model, it can be concluded that capsules take up proteins on surface by multilayer adsorption.
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Huang, Haoliang, e Guang Ye. "Numerical Studies of the Effects of Water Capsules on Self-Healing Efficiency and Mechanical Properties in Cementitious Materials". Advances in Materials Science and Engineering 2016 (2016): 1–10. http://dx.doi.org/10.1155/2016/8271214.
Testo completoAbstract (sommario):
In this research, self-healing due to further hydration of unhydrated cement particles is taken as an example for investigating the effects of capsules on the self-healing efficiency and mechanical properties of cementitious materials. The efficiency of supply of water by using capsules as a function of capsule dosages and sizes was determined numerically. By knowing the amount of water supplied via capsules, the efficiency of self-healing due to further hydration of unhydrated cement was quantified. In addition, the impact of capsules on mechanical properties was investigated numerically. The amount of released water increases with the dosage of capsules at different slops as the size of capsules varies. Concerning the best efficiency of self-healing, the optimizing size of capsules is 6.5 mm for capsule dosages of 3%, 5%, and 7%, respectively. Both elastic modulus and tensile strength of cementitious materials decrease with the increase of capsule. The decreasing tendency of tensile strength is larger than that of elastic modulus. However, it was found that the increase of positive effect (the capacity of inducing self-healing) of capsules is larger than that of negative effects (decreasing mechanical properties) when the dosage of capsules increases.
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Pisciotta, Alessandra, Michele De Maria, Tommaso Verdina, Elisa Fornasari, Anto de Pol e Gian Maria Cavallini. "Anterior Capsule of the Lens: Comparison of Morphological Properties and Apoptosis Induction following FLACS and Standard Phacoemulsification Surgery". BioMed Research International 2018 (2018): 1–8. http://dx.doi.org/10.1155/2018/7242837.
Testo completoAbstract (sommario):
Purpose. Comparative evaluation of morphological features of anterior capsules and apoptosis induction in epithelial cells after femtosecond laser-assisted cataract surgery (FLACS) and standard phacoemulsification surgery. Methods. Group 1: 30 FLACS anterior capsulotomies and Group 2: 30 manual anterior continuous curvilinear capsulorhexes. All patients were operated on by the same experienced surgeon. Morphological features of the anterior capsules and apoptosis induction in epithelial cells were evaluated. Results. All patients revealed a significant mean best-corrected visual acuity (BCVA) improvement 3 months after surgery, and no major intraoperative nor postoperative complications occurred. The capsular epithelium appeared to be preserved in both groups. Scanning electron microscopy analysis revealed irregular saw-tooth shaped edges in capsules from Group 1 whereas capsules from Group 2 showed regular and smooth edges. A statistically significant higher expression of the downstream apoptotic effector cleaved caspase 3 was observed in Group 1. Conclusions. The saw-tooth appearance was likely due to the progressive sequence of laser pulses on the capsule. The low energy/high frequency properties of the laser pulse, combined with an overlapped pulse pattern, resulted in highly continuous morphology of capsule edges. The higher apoptosis induction in FLACS group might be due to photodisruption-dependent plasma generation and formation of cavitation bubbles.
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Ruiz-Riancho, Ignacio Nilo, Alessio Alexiadis, Zhibing Zhang e Alvaro Garcia Hernandez. "A Discrete Multi-Physics Model to Simulate Fluid Structure Interaction and Breakage of Capsules Filled with Liquid under Coaxial Load". Processes 9, n. 2 (14 febbraio 2021): 354. http://dx.doi.org/10.3390/pr9020354.
Testo completoAbstract (sommario):
This paper investigated the mechanical response (including breakage and release of the internal liquid) of single core–shell capsules under compression by means of discrete multi-physics. The model combined Smoothed Particle Hydrodynamics for modelling the fluid and the Lattice Spring Model for the elastic membrane. Thanks to the meshless nature of discrete multi-physics, the model can easily account for the fracture of the capsule’s shell and the interactions between the internal liquid and the solid shell. The simulations replicated a parallel plate compression test of a single core–shell capsule. The inputs of the model were the size of the capsule, the thickness of the shell, the geometry of the internal structure, the Young’s modulus of the shell material, and the fluid’s density and viscosity. The outputs of the model were the fracture type, the maximum force needed for the fracture, and the force–displacement curve. The data were validated by reproducing equivalent experimental tests in the laboratory. The simulations accurately reproduced the breakage of capsules with different mechanical properties. The proposed model can be used as a tool for designing capsules that, under stress, break and release their internal liquid at a specific time.
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Saul, Lawrence K. "An EM Algorithm for Capsule Regression". Neural Computation 33, n. 1 (gennaio 2021): 194–226. http://dx.doi.org/10.1162/neco_a_01336.
Testo completoAbstract (sommario):
We investigate a latent variable model for multinomial classification inspired by recent capsule architectures for visual object recognition (Sabour, Frosst, & Hinton, 2017 ). Capsule architectures use vectors of hidden unit activities to encode the pose of visual objects in an image, and they use the lengths of these vectors to encode the probabilities that objects are present. Probabilities from different capsules can also be propagated through deep multilayer networks to model the part-whole relationships of more complex objects. Notwithstanding the promise of these networks, there still remains much to understand about capsules as primitive computing elements in their own right. In this letter, we study the problem of capsule regression—a higher-dimensional analog of logistic, probit, and softmax regression in which class probabilities are derived from vectors of competing magnitude. To start, we propose a simple capsule architecture for multinomial classification: the architecture has one capsule per class, and each capsule uses a weight matrix to compute the vector of hidden unit activities for patterns it seeks to recognize. Next, we show how to model these hidden unit activities as latent variables, and we use a squashing nonlinearity to convert their magnitudes as vectors into normalized probabilities for multinomial classification. When different capsules compete to recognize the same pattern, the squashing nonlinearity induces nongaussian terms in the posterior distribution over their latent variables. Nevertheless, we show that exact inference remains tractable and use an expectation-maximization procedure to derive least-squares updates for each capsule's weight matrix. We also present experimental results to demonstrate how these ideas work in practice.
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Stavarache, Carmen, e Larysa Paniwynk. "Tailoring Polyelectrolyte Magnetic Capsules". Materiale Plastice 55, n. 2 (30 giugno 2018): 192–95. http://dx.doi.org/10.37358/mp.18.2.4993.
Testo completoAbstract (sommario):
In the second part of this series polyelectrolyte multilayer capsules consisting of 6 bilayers of PAH/PSS and one layer of magnetic iron oxide nanoparticles namely D12, were fabricated. These capsules had their inner core removed once the 12 layers had been formed. The properties of the D12 capsules (mean diameter, concentration, dye intake and iron content) were analysed and compared with previously manufactured capsules which had the core dissolved after only 6 layers of coatings namely D6. The new sets of capsules had a greater capsule diameter, higher dye intake into the core and a higher iron oxide loading into the capsule layers.
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Robson, J., G. Snow, J. Y. Park, R. C. Moretz, H. O. Krenkel e A. Angel. "Microscopic evaluation of structural changes in brittle, hydrated, gelatin capsules". Proceedings, annual meeting, Electron Microscopy Society of America 50, n. 1 (agosto 1992): 780–81. http://dx.doi.org/10.1017/s0424820100124306.
Testo completoAbstract (sommario):
Gelatin capsules are a commonly used dosage form for prescription medications. Storage conditions as well as drug formulation can directly affect capsule integrity over time. Often, capsule brittleness following storage can be related to water loss. In this report an encapsulated drug formulation containing 77% anhydrous citric acid became brittle following two years of storage at 25° C/60% RH. However, Thermogravimetric data showed that capsule brittleness did not result from changes in water content. Both normal(without drug formulation) and brittle capsules contained 12% water. Microscopy was then applied to examine capsule walls to determine if the change in physical integrity could be related to a structural change.LM of normal capsules showed both the interior and exterior walls to be smooth, without indentations. SEM examination of the interior wall of the normal capsules revealed fairly smooth walls (Fig. 1). Sections of normal capsules examined with the TEM revealed intact walls with little variation between sections or capsules (Fig. 2). Examination of capsules stored for one year revealed interior surfaces stippled with particulate identified as active ingredient(AI) and citric acid. The particulate was not fused to the interior wall and no morphological changes were observed for the Al or citric acid when compared to known active/excipient morphology. In contrast, the interior wall of capsules stored for two years showed striking morphological changes. LM presented an eroded interior wall indicating a loss or redistribution of gelatin. TEM further illustrated that the structure of the capsule had been altered; subsurface pockets were seen throughout the section of the capsule (Fig. 3). TiO2 particles, a whitener used in the capsules, were redistributed in the areas where degradation was apparent. SEM presented irregular interior surfaces with abundant particulate fused to the capsule wall (Fig. 4). The fused particulate presented structure which contrasted with the known morphology of the citric acid and Al starting materials indicating that dissolution and recrystallization had taken place. Comparable crystal structure was determined when Al and citric acid were dissolved in water and allowed to recrystallize at room temperature.
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Hossain, Mirza Akram, Stéphanie Boily, Natasha Beauregard, Jean-Marc Forest e Grégoire Leclair. "Stability of Betaine Capsules". ISRN Pharmaceutics 2013 (3 giugno 2013): 1–4. http://dx.doi.org/10.1155/2013/458625.
Testo completoAbstract (sommario):
Betaine is used to treat homocystinuria and is not available in Canada as a formulated drug. In order to facilitate the administration of this compound to patients, a capsule formulation and an evaluation of its stability were required. Capsule formulations of betaine were developed (160 mg and 625 mg of betaine per capsule). As betaine has no chromophore, an HPLC-ELSD analytical method was also developed. The critical quality attributes of these formulations were evaluated (content assay, content uniformity, and dissolution) as well as their stability. Capsules with acceptable quality attributes were produced. These capsules remained stable for 1 year when stored in airtight containers at controlled room temperature. However, shelf life decreased dramatically in nonairtight containers at 30°C (3 months for the lactose-containing capsules of 160 mg and 6 months for the capsules of 625 mg).
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Uchimura, Érica Mayumi Takase, Irene Harumi Kamata Barcelos, Deborah Brandão de Paiva, Lucia Figueiredo Mourão e Agricio Nubiato Crespo. "Evaluation of the location of capsules swallowed with food during the pharyngeal phase triggering in asymptomatic adults". CoDAS 26, n. 6 (dicembre 2014): 476–80. http://dx.doi.org/10.1590/2317-1782/20140000045.
Testo completoAbstract (sommario):
OBJECTIVE: To assess the location of hard gelatin capsules in the pharyngeal phase triggering among asymptomatic adults. INTRODUCTION: The location of the bolus during the pharyngeal phase triggering provides information about the sensorimotor model of the beginning of deglutition onset. PURPOSE: To evaluate the location of hard gelatin capsules in the pharyngeal phase triggering among asymptomatic adults. METHODS: A videofluoroscopy swallowing study was carried out in 60 subjects (14 male and 46 female participants) aged between 27 and 55 years, who were evaluated with hard gelatin capsules #00 and #3 containing barium sulfate, swallowed with liquid food and pudding, in free volume. The first laryngeal elevation movement was the criterion to locate the pharyngeal phase triggering. Statistical analysis was based on the McNemar test. RESULTS: Capsule #3 presented higher percentage of location in the tongue dorsum compared to capsule #00, and capsule #00 presented higher percentage of location in the tongue base and vallecula compared to capsule #3. There was a difference between different capsules swallowed with liquid (p=0.016) and pudding (p=0.037). CONCLUSION: The capsule size influenced the location of the pharyngeal phase triggering. Smaller capsules started pharyngeal phase in the most anterior region (tongue dorsum) compared to larger capsules.
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Adu, Kwabena, Yongbin Yu, Jingye Cai, Victor Dela Tattrah, James Adu Ansere e Nyima Tashi. "S-CCCapsule: Pneumonia detection in chest X-ray images using skip-connected convolutions and capsule neural network". Journal of Intelligent & Fuzzy Systems 41, n. 1 (11 agosto 2021): 757–81. http://dx.doi.org/10.3233/jifs-202638.
Testo completoAbstract (sommario):
The squash function in capsule networks (CapsNets) dynamic routing is less capable of performing discrimination of non-informative capsules which leads to abnormal activation value distribution of capsules. In this paper, we propose vertical squash (VSquash) to improve the original squash by preventing the activation values of capsules in the primary capsule layer to shrink non-informative capsules, promote discriminative capsules and avoid high information sensitivity. Furthermore, a new neural network, (i) skip-connected convolutional capsule (S-CCCapsule), (ii) Integrated skip-connected convolutional capsules (ISCC) and (iii) Ensemble skip-connected convolutional capsules (ESCC) based on CapsNets are presented where the VSquash is applied in the dynamic routing. In order to achieve uniform distribution of coupling coefficient of probabilities between capsules, we use the Sigmoid function rather than Softmax function. Experiments on Guangzhou Women and Children’s Medical Center (GWCMC), Radiological Society of North America (RSNA) and Mendeley CXR Pneumonia datasets were performed to validate the effectiveness of our proposed methods. We found that our proposed methods produce better accuracy compared to other methods based on model evaluation metrics such as confusion matrix, sensitivity, specificity and Area under the curve (AUC). Our method for pneumonia detection performs better than practicing radiologists. It minimizes human error and reduces diagnosis time.
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Choi, Se-Jin, Ji-Hwan Kim, Hyojin Jeong, Ja-Sung Lee, Tae-Uk Lim, Haye Min Ko, Sung Hoon Kim e Wonsuk Jung. "Simulated and Experimental Investigation of the Mechanical Properties and Solubility of 3D-Printed Capsules for Self-Healing Cement Composites". Materials 14, n. 16 (15 agosto 2021): 4578. http://dx.doi.org/10.3390/ma14164578.
Testo completoAbstract (sommario):
In the concrete industry, various R&D efforts have been devoted to self-healing technology, which can maintain the long-term performance of concrete structures, which is important in terms of sustainable development. Cracks in cement composites occur and propagate because of various internal and external factors, reducing the composite’s stability. Interest in “self-healing” materials that can repair cracks has led researchers to embed self-healing capsules in cement composites. Overcoming the limitations of polymer capsules produced by chemical manufacturing methods, three-dimensional (3D) printing can produce capsules quickly and accurately and offers advantages such as high material strength, low cost, and the ability to fabricate capsules with complex geometries. We performed structural analysis simulations, experimentally evaluated the mechanical properties and solubility of poly(lactic acid) (PLA) capsules, and examined the effect of the capsule wall thickness and printing direction on cement composites embedded with these capsules. Thicker capsules withstood larger bursting loads, and the capsule rupture characteristics varied with the printing angle. Thus, the capsule design parameters must be optimized for different environments. Although the embedded capsules slightly reduced the compressive strength of the cement composites, the benefit of the encapsulated self-healing agent is expected to overcome this disadvantage.
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Le, D. V., e Zhijun Tan. "Hydrodynamic Interaction of Elastic Capsules in Bounded Shear Flow". Communications in Computational Physics 16, n. 4 (ottobre 2014): 1031–55. http://dx.doi.org/10.4208/cicp.090813.160414a.
Testo completoAbstract (sommario):
AbstractThis paper presents a modified Loop’s subdivision algorithm for studying the deformation of a single capsule, the hydrodynamic interaction between two capsules and the hydrodynamic diffusion of a suspension of capsules in bounded shear flow. A subdivision thin-shell model is employed to compute the forces generated on the surface of the elastic capsule during deformation. The capsule surface is approximated using the modified Loop’s subdivision scheme which guarantees bounded curvature and C1 continuity everywhere on the limit surface. The present numerical technique has been validated by studying the deformation of a spherical capsule in shear flow. Computations are also performed for a biconcave capsule over a wide range of shear rates and viscosity ratios to investigate its dynamics. In addition, the hydrodynamic interaction between two elastic capsules in bounded shear flow is studied. Depending on the wall separation distance, the trajectory-bifurcation points that separate reversing and crossing motions for both spherical and biconcave capsules can be found. Compared to the spherical capsules, the biconcave capsules exhibit additional types of interaction such as rotation and head-on collision. The head-on collision results in a large trajectory shift which contribute to the hydrodynamic diffusion of a suspension. A suspension of a large number of biconcave capsules in shear flow is also simulated to show the ability of the modified scheme in running a large-scale simulation over a long period of time.
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Glicksman, Caroline A., Michel A. Danino, Johnny I. Efanov, Arij El Khatib e Monica Nelea. "A Step Forward Toward the Understanding of the Long-Term Pathogenesis of Double Capsule Formation in Macrotextured Implants: A Prospective Histological Analysis". Aesthetic Surgery Journal 39, n. 11 (21 dicembre 2018): 1191–99. http://dx.doi.org/10.1093/asj/sjy293.
Testo completoAbstract (sommario):
Abstract Background Although increasingly reported in the literature, most plastic surgeons cannot define the etiology of double capsules. Often an incidental finding at implant exchange, double capsules are frequently associated with macrotextured devices. Several mechanisms have been proposed, including at the forefront that shearing causes a delamination of the periprosthetic capsule into a double capsule. Objectives This study was designed to confirm the hypothesis that mechanical forces are involved in formation of double capsules by histological analysis. Methods A prospective analysis of consecutive implants with double capsules removed over 2 years was performed. Data collected at the time of surgery included Baker classification, reason for explant, implant manufacturer and style, and any presence of a seroma associated with the capsule. Specimens were sent for analysis by histology utilizing hematoxylin and eosin and alpha-smooth muscle actin staining techniques. Results Eight double capsules were collected for specimen analysis. All capsules demonstrated evidence of granulation tissue, alpha-smooth muscle actin positive myofibroblasts, and folds with embedded texture. Fibrosis surrounded weak areas with presence of layering and splitting, creating a potential space that is prone to separation. Tears and folds from granulomatous reaction are also present within the outer layer of the double capsule, which can only be explained by a mechanical shearing force as a pathogenic mechanism. Conclusions Understanding the pathogenesis of double capsules may allow plastic surgeons to refine their indications for macrotextured implants while providing guidance to patients on avoidance of activities that produce shear-forces. The findings support the hypothesis that shearing forces delaminate the capsule into 2 separate distinct capsules. Level of Evidence: 5
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O’Grady, John, Siofra Bennett, Aidan Kaar, Lorraine Nolan, Julie O’Neill, Lucy Quinlivan e Martin Buckley. "Routine plain film of abdomen in asymptomatic patients with video capsule retention in small bowel-time to change practice?" Mini-invasive Surgery 6 (2022): 34. http://dx.doi.org/10.20517/2574-1225.2022.22.
Testo completoAbstract (sommario):
Aim: Small bowel capsule retention is rare, with a rate of approximately 2%, defined as visible retention on plain film of abdomen (PFA) after 14 days. Currently, PFA is performed if the capsule is not seen to reach the large bowel during recording. Alternatively, for upper gastrointestinal (UGI) capsule studies, the risk of retention is determined if the capsule fails to reach the small bowel during recording. Given the similar physical specifications of the capsules (Medtronic) used, we considered whether 14-day PFA is no longer required for small bowel capsules not observed in the large bowel. Methods: The use of patency capsules in our lab allows careful selection of small bowel capsule studies to minimize the risk of retention. All PFAs performed over a five-year period were reviewed to determine if careful selection and use of patency negate the need for capsule retention PFA screening. Results: In total, 688 small-bowel capsules were performed during the study period, and 3.6% had prior patency capsules. Thirty-one PFAs with a query of capsule retention were performed during the study period on 28 patients. This included 15 females, and the median age was 53.5 years. None of the films demonstrated capsule retention. Conclusion: Our data suggest that 14-day PFA may no longer be required for small bowel capsules not seen to reach the large bowel. Advice regarding symptoms of capsule retention and precaution with magnetic resonance imaging, similar to current UGI capsule advice, may suffice. This may reduce the burden on radiology imaging slots and, in particular, eliminate unnecessary radiation exposure and repeat hospital attendance for patients.
29
Wu, G. X., J. Ding e J. M. Xue. "Synthesis of calcium carbonate capsules in water-in-oil-in-water double emulsions". Journal of Materials Research 23, n. 1 (gennaio 2008): 140–49. http://dx.doi.org/10.1557/jmr.2008.0017.
Testo completoAbstract (sommario):
Hollow capsules have been intensively investigated due to their high capacity of encapsulating large quantities of guest molecules, making them promising candidate materials for various encapsulation applications. In this work, CaCO3 hollow capsules were successfully synthesized via an emulsion route. The interior hollow structure of the capsules was confirmed by using scanning electron microscopy and transmission electron microscopy (TEM). The vaterite polymorph of the as-synthesized CaCO3 capsules was determined by using x-ray diffraction, high-resolution TEM, and Fourier transform infrared spectroscopy. A self-assembly model was proposed to explain the formation mechanism of the vaterite capsules. By adjusting experimental parameters such as the internal solution amount and the surfactant amount of the double-emulsion system, the average capsule size could be adjusted accordingly. However, the increase in capsule size was at a compensation of size-uniformity degradation. The capsule size uniformity was then further optimized by increasing the magnetic stirring rate. The resultant vaterite capsules demonstrated biodegradability behavior after immersion in phosphate-buffered saline solution, leading to their promising applications in the area of controlled drug delivery.
30
Dimitrakopoulos, P. "Effects of membrane hardness and scaling analysis for capsules in planar extensional flows". Journal of Fluid Mechanics 745 (24 marzo 2014): 487–508. http://dx.doi.org/10.1017/jfm.2014.66.
Testo completoAbstract (sommario):
AbstractIn this paper, we investigate computationally the effects of membrane hardness on the dynamics of strain-hardening capsules in planar extensional Stokes flows. As the flow rate increases, all capsules reach elongated steady-state configurations but the cross-section of the more strain-hardening capsules preserves its elliptical shape while the less strain-hardening capsules become lamellar. The capsule deformation in strong extensional flows is accompanied with very pointed edges, i.e. large edge curvatures and thus small local edge length scales, which makes the current investigation a multi-length interfacial dynamics problem. Our computational results for elongated strain-hardening capsules are accompanied with a scaling analysis which provides physical insight on the extensional capsule dynamics. The two distinct capsule conformations we found, i.e. the slender spindle and lamellar capsules, are shown to represent two different types of steady-state extensional dynamics. The former are stabilized mainly via the membrane’s shearing resistance and the latter via its area-dilatation resistance, associated with the elongation tension normal forces and thus both types differ from bubbles which are stabilized mainly via the lateral surface-tension normal forces. Our steady-state deformation results can be used to identify the elastic properties of a real capsule, i.e. the membrane’s shear and area-dilatation moduli, utilizing a single experimental technique.
31
Buffet, Amandine, Eduardo P. C. Rocha e Olaya Rendueles. "Nutrient conditions are primary drivers of bacterial capsule maintenance in Klebsiella". Proceedings of the Royal Society B: Biological Sciences 288, n. 1946 (3 marzo 2021): 20202876. http://dx.doi.org/10.1098/rspb.2020.2876.
Testo completoAbstract (sommario):
The fitness cost associated with the production of bacterial capsules is considered to be offset by the protection provided by these extracellular structures against biotic aggressions or abiotic stress. However, it is unknown if the capsule contributes to fitness in the absence of these. Here, we explored conditions favouring the maintenance of the capsule in Klebsiella pneumoniae, where the capsule is known to be a major virulence factor. Using short-term experimental evolution on different Klebsiella strains, we showed that small environmental variations have a strong impact on the maintenance of the capsule. Capsule inactivation is frequent in nutrient-rich, but scarce in nutrient-poor media. Competitions between wild-type and capsule mutants in nine different strains confirmed that the capsule is costly in nutrient-rich media. Surprisingly, these results also showed that the presence of a capsule provides a clear fitness advantage in nutrient-poor conditions by increasing both growth rates and population yields. The comparative analyses of the wild-type and capsule mutants reveal complex interactions between the environment, genetic background and serotype even in relation to traits known to be relevant during pathogenesis. In conclusion, our data suggest there are novel roles for bacterial capsules yet to be discovered and further supports the notion that the capsule's role in virulence may be a by-product of its contribution to bacterial adaptation outside the host.
32
Xu, Shi, Amir Tabaković, Xueyan Liu, Damian Palin e Erik Schlangen. "Optimization of the Calcium Alginate Capsules for Self-Healing Asphalt". Applied Sciences 9, n. 3 (30 gennaio 2019): 468. http://dx.doi.org/10.3390/app9030468.
Testo completoAbstract (sommario):
It has been demonstrated that calcium alginate capsules can be used as an asphalt healing system by pre-placing rejuvenator (healing agent) into the asphalt mix and releasing the rejuvenator on demand (upon cracking). This healing mechanism relies on the properties of capsules which are determined by the capsule preparation process. In this study, to optimize the calcium alginate capsules, capsules are prepared using varying Alginate/Rejuvenator (A/R) ratios. Light microscope microscopy and Environmental Scanning Electron Microscope (ESEM) are employed to characterize the morphology and microstructure of these capsules. Thermal stability and mechanical property are investigated by thermogravimetric analysis (TGA) and compressive tests. The testing results indicate that higher alginate content results in smaller diameter and lower thermal resistance, but higher compressive strength. The optimum A/R ratio of calcium alginate capsules is found to be 30/70. To prove the effectiveness of the optimized capsules, the capsules are embedded in asphalt mortar beams and a bending and healing program is carried out. The effect of capsule shell material on the mechanical response of asphalt mixture is evaluated through three-point bending on the mortar beams embedded with blank capsules (without the healing agent). Aged mortar beams containing alginate capsules encapsulating rejuvenator demonstrate a higher strength recovery after bending tests, which indicates effective healing due to the release of the rejuvenators from the capsules.
33
Kanashima, Junsyou, Naohiro Sugita e Tadahiko Shinshi. "Number concentration dependence of ultrasonic disruption ratio of diameter-sorted microcapsules". Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 236, n. 4 (10 gennaio 2022): 557–65. http://dx.doi.org/10.1177/09544119211070343.
Testo completoAbstract (sommario):
The use of ultrasound to destroy microcapsules in microbubble-assisted drug delivery systems (DDS) is of great interest. In the present study, the disruption ratios of capsule clusters were measured by observing and experimentally analyzing microcapsules with polymer shells undergoing disruption by ultrasound. The microcapsules were dispersed in a planar microchamber filled with a gelatin gel and sonicated using 1 MHz focused ultrasound. Different capsule populations were obtained using a filtration technique to modify and control the capsule sizes. The disruption ratio as a function of the concentration of capsules was obtained through image processing of the recorded photomicrographs. We found that the disruption ratio for each population exponentially decreases as the particle number concentration (PNC) increases. The maximum disruption ratio of the diameter-sorted capsules was larger than that of polydispersed capsules. Particularly, for resonant capsule populations, the ratio was more than twice that of polydispersed capsules. Furthermore, the maximum disruption ratio occurred at higher concentrations as the mean particle diameter of the capsule cluster decreased.
34
Matsuoka, Hiroyoshi, Koutarou Maeda, Hidetoshi Katsuno, Akira Tsunoda, Keiji Koda, Hiroki Ohge, Masatoshi Oya, Kazuhiko Yoshioka, Yoshihiro Imazu e Tadahiko Masaki. "Recovery of Upper Gastrointestinal Bowel Movement After Rectosigmoid Cancer Surgery: A Pilot Transit Analysis". International Surgery 96, n. 4 (1 ottobre 2011): 281–85. http://dx.doi.org/10.9738/cc51.1.
Testo completoAbstract (sommario):
Abstract Postoperative gastrointestinal bowel transit right after colorectal resection has not yet been clarified. Thirty patients with rectosigmoid cancer were treated in this pilot study. The nasogastric tube was removed on the first postoperative day. One Sitzmarks capsule was given to each patient on the second postoperative day. Abdominal X-rays were taken at 3, 6, 8, 24, 48, and 72 hours after capsule intake. Distribution of the remaining Sitzmarks capsules were counted on X-ray films to clarify postoperative gastrointestinal movement after bowel resection. All Sitzmarks capsules were observed in the stomach at 3 and 6 hours after capsule intake. At 8 hours (second postoperative day), the Sitzmarks capsules were distributed from the stomach to the small intestine. Sitzmarks capsules were distributed in the right side colon at 24 hours (third postoperative day) after intake. Although the main distribution was still in the right side colon, several patients had evacuations accompanied by the disappearance of the Sitzmarks capsules. In 50% of the patients, it took approximately 72 hours (fifth postoperative day) for the first defecation after intake of the capsules. However, the Sitzmarks capsules remained mainly in the right side colon. Eight hours after intake, the majority of the Sitzmarks capsules shifted to the small intestine. Therefore, medication or feeding should be safely possible starting on the second postoperative day. There was no particular impact of bowel resection on upper gastrointestinal transit in patients with rectosigmoid cancer.
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Taylor, Clare M., Marie Goldrick, Liz Lord e Ian S. Roberts. "Mutations in the waaR Gene of Escherichia coli Which Disrupt Lipopolysaccharide Outer Core Biosynthesis Affect Cell Surface Retention of Group 2 Capsular Polysaccharides". Journal of Bacteriology 188, n. 3 (1 febbraio 2006): 1165–68. http://dx.doi.org/10.1128/jb.188.3.1165-1168.2006.
Testo completoAbstract (sommario):
ABSTRACT On the basis of increased resistance to K5 capsule-specific bacteriophage, a waaR transposon mutant defective in the biosynthesis of lipopolysaccharide outer core was isolated. In a K1-expressing strain the mutation equally affected sensitivity to K1 capsule-specific bacteriophage, indicating a general effect on group 2 capsules. The waaR mutation affected retention on the cell surface of the K5 polysaccharide, with increased polysaccharide accumulating in the culture supernatant. This indicates that interactions between the outer core of lipopolysaccharide and group 2 capsular polysaccharides are important for the stabilization of group 2 capsular polysaccharides on the cell surface.
36
Richmond, Annalise, David C. Schwebel, Casie H. Morgan, Zhiwu W. Liang, Alice Boutoille, Pablo Buso, Ana Mata e Gerard Stijntjes. "The exploration of size and toddler interaction with liquid laundry detergent capsules". PLOS ONE 15, n. 12 (30 dicembre 2020): e0244481. http://dx.doi.org/10.1371/journal.pone.0244481.
Testo completoAbstract (sommario):
Liquid laundry capsules have been involved in multiple poisoning incidents with young children in the home. There are a range of contributing factors for these incidents, including influences from industry, culture, home environments, and parenting/supervision. There also are influences from children’s behaviour and decisions in reaction to potential hazards. Previous research examined the influence of capsule product appearance and colour on children’s behaviour around hazardous household items, but little research examines the influence of product size. This research explored if differences in the size of liquid laundry capsules result in different levels of toddler interaction. We compared two commercially available capsule designs that are identical in physical appearance but differ in physical size. Our research was conducted using three studies: Study 1, forced-choice test in an out-of-context laboratory setting; Study 2, an ecologically-valid, simulated real-world setting replicating a home laundry cabinet with a container of capsules left open; and Study 3, a second ecologically-valid study replicating a home laundry cabinet, this time with a capsule left outside its container. Capsule interaction was measured by grasping choice among samples of 156 toddlers ages 9–36 months. The same sample was used for Studies 1 and 2, and a second identically sized sample recruited for Study 3. Results from Study 1 indicated toddlers selected the small (49.8% selection) and large (50.2%) capsule with nearly identical frequency. Study 2 largely replicated Study 1: Toddlers selected the small capsule or container of small capsules 26.8% of the time and the large capsule or container of large capsules 22.3% of the time. Study 3 also replicated previous findings: Toddlers selected the smaller capsule 18.0% of the time and the larger 19.2%. We discuss study results, which suggest no appreciable difference in toddler’s grasping choice to smaller versus larger laundry capsules.
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Peters, Walter, Dennis Smith, Harvey Grosman e Victor Fornasier. "Role of mammography to assess complications of silicone gel breast implants". Canadian Journal of Plastic Surgery 3, n. 3 (agosto 1995): 1–9. http://dx.doi.org/10.1177/229255039500300308.
Testo completoAbstract (sommario):
Mammography is not accurate to predict implant rupture in most patients. Its sensitivity rate is only 11 to 16%. However, two mammographic findings appear to suggest implant rupture: the appearance of large areas of implant herniation, and the appearance of silicone globules lying outside the margins of the implant. Mammography is also helpful to predict capsular calcification and to assess certain complications of retained breast implant capsules. Two patients presented with retained capsules which had not resolved, two and five years after implant removal. One patient developed a spiculated mass, suspicious for carcinoma, that proved to be a cystic mass resulting from persistent serous effusion. The other patient demonstrated a large densely calcified capsule which interfered with breast imaging.
38
Ge, Liqin, Xing Wang, Long Ba e Zhongze Gu. "Hydrogen-Bonding Layer Protecting Polyelectrolyte Capsules and Its Mechanical Property Study with Atomic Force Microscope". Journal of Nanoscience and Nanotechnology 8, n. 6 (1 giugno 2008): 2996–3002. http://dx.doi.org/10.1166/jnn.2008.156.
Testo completoAbstract (sommario):
The hydrogen-bonding multilayered polyelectrolyte capsules with sizes around 6 μm were fabricated by layer-by-layer self-assembly method. The morphology of the obtained capsules was observed with Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM) and Atomic Force Microscope (AFM), respectively. The elastic properties of the capsules were studied with AFM. The capsule was pressed by cantilever with different lengths, a glass bead glued at the end of the cantilever. The force curves were measured on the capsule in air. The Young's modulus of the capsule was obtained (E = 170 MPa for the loading). Results show that this model can predict the elastic deformation of the microcapsule. The accuracy of the elastic deformation of polymer capsule can be ensured using a cantilever of mediate stiffness. Our results show that the existence of the hydrogen-bonding layer makes the multilayered polyelectrolyte harder in comparison with the pure multilayered polyelectrolyte capsules.
39
Coclite, Alessandro, e Alberto M. Gambaruto. "Injection of Deformable Capsules in a Reservoir: A Systematic Analysis". Fluids 4, n. 3 (3 luglio 2019): 122. http://dx.doi.org/10.3390/fluids4030122.
Testo completoAbstract (sommario):
Motivated by red blood cell dynamics and injectable capsules for drug delivery, in this paper, a computational study of capsule ejection from a narrow channel into a reservoir is undertaken for a combination of varying deformable capsule sizes and channel dimensions. A mass-spring membrane model is coupled to an Immersed Boundary–Lattice Boltzmann model solver. The aim of the present work is the description of the capsules’ motion, deformation and the response of the fluid due to the complex particles’ dynamics. The interactions between the capsules affect the local velocity field and are responsible for the dynamics observed. Capsule membrane deformability is also seen to affect inter-capsule interaction. We observe that the train of three particles locally homogenises the velocity field and the leading capsule travels faster than the other two trailing capsules. Variations in the size of reservoir do not seem to be relevant, while the ratio of capsule diameter to channel diameter as well as the ratio of capsule diameter to inter-capsule spacing play a major role. This flow set-up has not been covered in the literature, and consequently we focus on describing capsule motion, membrane deformation and fluid dynamics, as a preliminary investigation in this field.
40
Su, Hai-Nan, Zhi-Hua Chen, Sheng-Bo Liu, Li-Ping Qiao, Xiu-Lan Chen, Hai-Lun He, Xian Zhao, Bai-Cheng Zhou e Yu-Zhong Zhang. "Characterization of Bacterial Polysaccharide Capsules and Detection in the Presence of Deliquescent Water by Atomic Force Microscopy". Applied and Environmental Microbiology 78, n. 9 (17 febbraio 2012): 3476–79. http://dx.doi.org/10.1128/aem.00207-12.
Testo completoAbstract (sommario):
ABSTRACTWe detected polysaccharide capsules fromZunongwangia profundaSM-A87 with atomic force microscopy (AFM). The molecular organization of the capsules at the single-polysaccharide-chain level was reported. Furthermore, we found that with ScanAsyst mode the polysaccharide capsules could be detected even in the presence of deliquescent water covering the capsule.
41
Hall, L. J., J. Brodie, B. J. Wood e M. R. Carroll. "Iron and water losses from hydrous basalts contained in Au80Pd20 capsules at high pressure and temperature". Mineralogical Magazine 68, n. 1 (febbraio 2004): 75–81. http://dx.doi.org/10.1180/0026461046810172.
Testo completoAbstract (sommario):
AbstractWe have performed experiments to determine the extents to which Fe and H2O are lost from hydrous basaltic melts contained in Au80Pd20 and graphite-lined Pt capsules at 0.7 –1 GPa and 1300–1350°C. All experiments were performed in the piston-cylinder apparatus. In order to minimize the possibility of rupture of the AuPd capsule and to control H2O loss we used a double-capsule method. The inner welded 2 mm diameter Au80Pd20 capsule was placed inside a welded 3 mm diameter Pt capsule, the intervening space being packed with hydrous sample. Loss of FeO* from the sample was found to be ≤4% relative in both the Au80Pd20 and graphite-lined Pt capsules in experiments of up to 24 h duration. Loss of H2O is greater and it depends on the oxidation state of the starting materials and the nature of the capsule. For starting mixes fired at 1 log fO2 unit above the quartz-fayalite-magnetite (QFM) buffer at 1 atm, H2O loss from Au80Pd20 capsules averaged 9% relative. Starting mixes fired at 1 log fO2 unit below the QFM buffer at 1atm lost, on average, 32% of their H2O when run in Au80Pd20 capsules at high pressure. All samples run in graphite-lined Pt capsules experienced dramatic H2O loss, averaging 52% relative, irrespective of initial oxidation state. We conclude that Au80Pd20 capsules are suitable for high-pressure hydrous melting experiments and that the sample loses very little Fe. In order to minimize H2O-loss, however, it is important that the starting materials be relatively oxidized.
42
Gao, Guo Feng, Lian Yong Yu, Bin Yao e Ying Bo Chen. "Preparation of Polymer Capsules for Solid Hydrogen Storage". Materials Science Forum 743-744 (gennaio 2013): 29–34. http://dx.doi.org/10.4028/www.scientific.net/msf.743-744.29.
Testo completoAbstract (sommario):
Phase inversion of polymer solution by immersion-precipitation method was used to prepare porous hollow capsule nickel boride composite. The composite was used as a carrier for sodium borohydride, in which sodium borohydride was absorbed into the capsules or embedded in the capsules during the processing of capsules formation. The preparation method and adsorption property of the polymer capsules were studied. The effect of capsules structure on the storage capacity of sodium borohydride was investigated. The results showed that capsules prepared by 18wt% of PVDF-DMF solution with adding 15% PVP had the best adsorption capacity. While capsules prepared by PVA had better affinity to water, this made them easier to absorb sodium borohydride in the aqueous solution.
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Sinha, Arkabrata, Qi Wang e Jianqiang Wei. "Feasibility and Compatibility of a Biomass Capsule System in Self-Healing Concrete". Materials 14, n. 4 (18 febbraio 2021): 958. http://dx.doi.org/10.3390/ma14040958.
Testo completoAbstract (sommario):
Cracking can facilitate deteriorations of concrete structures via various mechanisms by providing ingress pathways for moisture and aggressive chemicals. In contrast to conventional maintenance methods, self-healing is a promising strategy for achieving automatic crack repair without human intervention. However, in capsule-based self-healing concrete, the dilemma between capsules’ survivability and crack healing efficiency is still an unfathomed challenge. In this study, the feasibility of a novel property-switchable capsule system based on a sustainable biomass component, polylactic acid, is investigated. Capsules with different geometries and dimensions were studied focusing on the compatibility with concrete, including survivability during concrete mixing, influence on mortar and concrete properties, and property evolution of the capsules. The results indicate that the developed elliptical capsules can survive regular concrete mixing with a survival ratio of 95%. In concrete containing 5 vol.% of gravel-level capsules, the compressive strength was decreased by 13.5% after 90 days, while the tensile strength was increased by 4.8%. The incorporation of 2 vol.% of sand-level capsules did not impact the mortar strength. Degradation and switchable properties triggered by the alkaline matrix of cement were observed, revealing the potential of this novel biomass capsule system in achieving both high survivability and self-healing efficiency in concrete.
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Kim, Yong Jic, Yun Wang Choi e Sung-Rok Oh. "A Study on the Healing Performance of Solid Capsules for Crack Self-Healing of Cementitious Composites". Crystals 12, n. 7 (17 luglio 2022): 993. http://dx.doi.org/10.3390/cryst12070993.
Testo completoAbstract (sommario):
The purpose of this study is to investigate the healing performance of solid capsules made of cement as a basis for manufacturing self-healing capsules that can heal cracks in cementitious composites. The solid capsules were mixed with 5%, 10%, and 15% concentrations on the cement. The self-healing performance of cementitious composites with solid capsules was investigated through three evaluations. First, the mechanical strength-healing performance was evaluated through a re-loading test. Second, the durability-healing performance was evaluated through a permeability test. Finally, the crack-healing performance was examined by observing the crack widths. Through evaluation of the healing performance of the solid capsules, the healing performance of the compressive strength was found to be high when the capsule proportion was 10% and its size was within the range of 300 μm to 850 μm. Furthermore, the splitting tensile strength showed a high healing performance when the capsule proportion mixed was 15% and its size was 850 μm. In the case of the permeability test, a capsule size of 850 μm showed a healing effect greater than 95%. Cracks with a width of up to 200 μm tended to heal using capsules with a size of 600 μm to 850 μm.
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Wari, Ahmad Muzzayin Dina, Setiamurti Rahardjo e Dea Aulia Widyaevan. "KENYAMANAN INAP AT CAPSULE HOSTEL SEBAGAI DESAIN COMPACT". Jurnal Dimensi Seni Rupa dan Desain 16, n. 2 (1 febbraio 2020): 153–66. http://dx.doi.org/10.25105/dim.v16i2.7059.
Testo completoAbstract (sommario):
AbstractThe increasing number of millennial travelers has affected the growth of backpacker accommodations in Bandung, especially those which are built in a form of capsules. Located at the city center of Bandung, “Inap at Capsule Hostel” has many facilities, all of which are installed inside the capsules and make the design compact. Although all of those facilities are dimensionally accommodated, the anthropometric comfort of the capsule is still questionable since there are spaces required for body movements. With combining the qualitative method through experiencing the capsule’s interior directly and the quantitative method through analyzing reviews from booking websites with the instrument word cloud text analysis, it is found that the compact design of Inap at Capsule Hostel still represents the anthropometric comfort regardless its limited dimension. Nevertheless, rearrangement of some lighting facilities and materials inside the capsules is suggested to improve the quality of the spatial comfort. AbstrakMeningkatnya wisatawan milenial menjadi salah satu faktor pendorong berkembangnya penginapan backpacker berbentuk kapsul di kota Bandung. Inap at Capsule Hostel yang terletak di pusat kota Bandung memiliki lima belas fasilitas yang semuanya terletak di dalam unit kapsulnya dan membuat desainnya padat. Meskipun seluruh fasilitas tersebut dapat tertampung secara dimensi, tapi hal ini belum tentu sejalan dengan kenyamanan kapsul ini saat digunakan karena tubuh manusia memiliki aktivitas gerak yang membutuhkan ruang tambahan. Dengan memadukan metode kualitatif melalui pengalaman ruang secara langsung dan metode kuantitatif melalui olahan data review dari situs pemesanan akomodasi dengan word cloud text analysis, ternyata ditemukan bahwa unit yang padat pada Inap at Capsule Hostel masih nyaman digunakan meski secara dimensi terhitung sempit bagi ruang gerak manusia. Meskipun demikian, disarankan adanya penataan ulang beberapa fasilitas pencahayaan serta penggunaan material untuk meningkatkan kualitas kenyamanan ruangnya.
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Li, Boxin, Boyang Liu, Dapeng Han e Zhaokui Wang. "Autonomous Tracking of ShenZhou Reentry Capsules Based on Heterogeneous UAV Swarms". Drones 7, n. 1 (27 dicembre 2022): 20. http://dx.doi.org/10.3390/drones7010020.
Testo completoAbstract (sommario):
The safe landing and rapid recovery of the reentry capsules are very important to manned spacecraft missions. A variety of uncertain factors, such as flight control accuracy and wind speed, lead to a low orbit prediction accuracy and a large landing range of reentry capsules. It is necessary to realize the autonomous tracking and continuous video observation of the reentry capsule during the low-altitude phase. Aiming at the Shenzhou return capsule landing mission, the paper proposes a new approach for the autonomous tracking of Shenzhou reentry capsules based on video detection and heterogeneous UAV swarms. A multi-scale video target detection algorithm based on deep learning is developed to recognize the reentry capsules and obtain positioning data. A self-organizing control method based on virtual potential field is proposed to realize the cooperative flight of UAV swarms. A hardware-in-the-loop simulation system is established to verify the method. The results show that the reentry capsule can be detected in four different states, and the detection accuracy rate of the capsule with parachute is 99.5%. The UAV swarm effectively achieved autonomous tracking for the Shenzhou reentry capsule based on the position obtained by video detection. This is of great significance in the real-time searching of reentry capsules and the guaranteeing of astronauts’ safety.
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Lee, Boon-Beng, Rohaida Ibrahim, Sue-Yin Chu, Nurul Ainina Zulkifli e Pogaku Ravindra. "Alginate liquid core capsule formation using the simple extrusion dripping method". Journal of Polymer Engineering 35, n. 4 (1 maggio 2015): 311–18. http://dx.doi.org/10.1515/polyeng-2014-0174.
Testo completoAbstract (sommario):
Abstract Liquid core capsules have been widely used in various biotechnological applications. The capsules could be formed by the simple extrusion dripping method. However, the method requires strict control of several process variables in order to form spherical capsules. The aim of this study was to systematically investigate the influence of process variables of the method on the capsule size and shape. The results showed that the capsules diameter was decreased when the concentration of alginate solution was increased. The capsule diameter was increased when the gelation time and dripping tip diameter were increased. The membrane thickness of the capsules was significantly increased by the concentration of calcium chloride, gelation time and dripping tip diameter. However, the concentration of alginate gave the opposite trend on the membrane thickness of the capsules. As a recommendation, uniform and spherical alginate liquid core capsules could be formed when concentration of calcium chloride was >10 g/l, the concentration of alginate solution was >5 g/l and <20 g/l, gelation solution height in between 1.7 cm and 3.2 cm, and stirring rate of the gelation bath was in the range of 400–500 rpm.
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Gubbels, G. H., D. M. Bonner e E. O. Kenaschuk. "Indicators for optimum stage for swathing oilseed flax". Canadian Journal of Plant Science 74, n. 2 (1 aprile 1994): 323–25. http://dx.doi.org/10.4141/cjps94-061.
Testo completoAbstract (sommario):
Four maturity indicators were evaluated for determining the optimum time to swath flax. The indicators — percentage brown capsules determined by counting, percentage brown capsules determined by visual estimate, percentage green capsules determined by counting and capsule moisture — were found to be of similar value. Key words: Flax, Linum usitatissimum, swathing time, maturity
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Jeannot, Lucas, Michael Bell, Ryan Ashwell, Dmitry Volodkin e Anna Vikulina. "Internal Structure of Matrix-Type Multilayer Capsules Templated on Porous Vaterite CaCO3 Crystals as Probed by Staining with a Fluorescence Dye". Micromachines 9, n. 11 (25 ottobre 2018): 547. http://dx.doi.org/10.3390/mi9110547.
Testo completoAbstract (sommario):
Multilayer capsules templated on decomposable vaterite CaCO3 crystals are widely used as vehicles for drug delivery. The capsule represents typically not a hollow but matrix-like structure due to polymer diffusion into the porous crystals during multilayer deposition. The capsule formation mechanism is not well-studied but its understanding is crucial to tune capsule structure for a proper drug release performance. This study proposes new approach to noninvasively probe and adjust internal capsule structure. Polymer capsules made of poly(styrene-sulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDAD) have been stained with fluorescence dye rhodamine 6G. Physical-chemical aspects of intermolecular interactions required to validate the approach and adjust capsule structure are addressed. The capsules consist of a defined shell (typically 0.5–2 µm) and an internal matrix of PSS-PDAD complex (typically 10–40% of a total capsule volume). An increase of ionic strength and polymer deposition time leads to the thickening of the capsule shell and formation of a denser internal matrix, respectively. This is explained by effects of a polymer conformation and limitations in polymer diffusion through the crystal pores. We believe that the design of the capsules with desired internal structure will allow achieving effective encapsulation and controlled/programmed release of bioactives for advanced drug delivery applications.
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Yang, Xu Dong, Liang Liang Jin, Jia Chun Li e Dong Sun. "Explosion Simulation and Analysis of Coal Mine Rescue Capsule". Applied Mechanics and Materials 143-144 (dicembre 2011): 536–40. http://dx.doi.org/10.4028/www.scientific.net/amm.143-144.536.
Testo completoAbstract (sommario):
Coal mine rescue capsules, whose structural strength defines miners' safety directly, are becoming important equipments for miners' underground escaping. In order to improve the rescue capsule's strength, in this study the finite element model was established in ABAQUS environment, and the influence on rescue capsule made by the pressure of gas explosion was obtained by using explicit integration method. The maximum stress of rescue capsule appears at the corner where it has stress singularity and the central part of the stiffeners where the stress reached the yield strength. But the overall stress is within the allowable range.