scholarly journals Porous Alginate Scaffolds Assembled Using Vaterite CaCO3 Crystals

Micromachines ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 357 ◽  
Author(s):  
Alena Sergeeva ◽  
Anna S. Vikulina ◽  
Dmitry Volodkin

Formulation of multifunctional biopolymer-based scaffolds is one of the major focuses in modern tissue engineering and regenerative medicine. Besides proper mechanical/chemical properties, an ideal scaffold should: (i) possess a well-tuned porous internal structure for cell seeding/growth and (ii) host bioactive molecules to be protected against biodegradation and presented to cells when required. Alginate hydrogels were extensively developed to serve as scaffolds, and recent advances in the hydrogel formulation demonstrate their applicability as “ideal” soft scaffolds. This review focuses on advanced porous alginate scaffolds (PAS) fabricated using hard templating on vaterite CaCO3 crystals. These novel tailor-made soft structures can be prepared at physiologically relevant conditions offering a high level of control over their internal structure and high performance for loading/release of bioactive macromolecules. The novel approach to assemble PAS is compared with traditional methods used for fabrication of porous alginate hydrogels. Finally, future perspectives and applications of PAS for advanced cell culture, tissue engineering, and drug testing are discussed.

2020 ◽  
Vol 90 (19-20) ◽  
pp. 2223-2244
Author(s):  
Jiaqi Yan ◽  
Victor E Kuzmichev

Customization is prevailing in the apparel industry with increasing requirements from consumers and the popularization of new technologies. This study aimed to establish the novel approach of applying existing and new body measurements to customize the pattern block of a men's shirt, to enrich the anthropometric database, and to develop the fit evaluation procedure. New body measurements were extracted from 156 scanned male mesh bodies in accordance with the morphological features and developing method of pattern block sketching. Owing to these new body measurements, the customized shirt with assured high-level fit can be obtained by generating original patterns as bespoke, on the one hand, and by transforming ready-to-wear patterns, on the other hand. The first way is e-bespoke tailoring that utilizes the developed schedule of body morphological features, improved shirt pattern of desired style (body fit, slim fit, regular fit, and comfort fit), and virtual try-on software CLO 3D. The proposed method of virtual e-bespoke design allows readily completing a well-fitted and balanced men's shirt, which will contribute to the efficiency of customization and quality of end-products for the apparel industry.


2016 ◽  
Vol 23 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Alessia Matruglio ◽  
Simone Dal Zilio ◽  
Rudi Sergo ◽  
Riccardo Mincigrucci ◽  
Cristian Svetina ◽  
...  

A new high-performance method for the free-electron laser (FEL) focused beam diagnosis has been successfully tested at the FERMI FEL in Trieste, Italy. The novel pixelated phosphor detector (PPD) consists of micrometric pixels produced by classical UV lithography and dry etching technique, fabricated on a silicon substrate, arranged in a hexagonal geometry and filled with suitable phosphors. It has been demonstrated that the overall resolution of the system has increased by reducing the diffusion of the light in the phosphors. Various types of PPD have been produced and tested, demonstrating a high resolution in the beam profile and the ability to measure the actual spot size shot-to-shot with an unprecedented resolution. For these reasons, the proposed detector could become a reference technique in the FEL diagnosis field.


Mathematics ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 244
Author(s):  
Cristian Napole ◽  
Oscar Barambones ◽  
Mohamed Derbeli ◽  
Isidro Calvo ◽  
Mohammed Yousri Silaa ◽  
...  

Piezoelectric actuators (PEA) are frequently employed in applications where nano-Micr-odisplacement is required because of their high-precision performance. However, the positioning is affected substantially by the hysteresis which resembles in an nonlinear effect. In addition, hysteresis mathematical models own deficiencies that can influence on the reference following performance. The objective of this study was to enhance the tracking accuracy of a commercial PEA stack actuator with the implementation of a novel approach which consists in the use of a Super-Twisting Algorithm (STA) combined with artificial neural networks (ANN). A Lyapunov stability proof is bestowed to explain the theoretical solution. Experimental results of the proposed method were compared with a proportional-integral-derivative (PID) controller. The outcomes in a real PEA reported that the novel structure is stable as it was proved theoretically, and the experiments provided a significant error reduction in contrast with the PID.


2014 ◽  
Vol 11 (4) ◽  
pp. 1337-1359
Author(s):  
Jakub Křoustek ◽  
Fridolín Pokorný ◽  
Dusan Kolář

Retargetable executable-code decompilation is a one of the most complicated reverse-engineering tasks. Among others, it involves de-optimization of compiler-optimized code. One type of such an optimization is usage of so-called instruction idioms. These idioms are used to produce faster or even smaller executable files. On the other hand, decompilation of instruction idioms without any advanced analysis produces almost unreadable high-level language code that may confuse the user of the decompiler. In this paper, we revisit and extend the previous approach of instruction-idioms detection used in a retargetable decompiler developed within the Lissom project. The previous approach was based on detection of instruction idioms in a very-early phase of decompilation (a front-end part) and it was inaccurate for architectures with a complex instruction set (e.g. Intel x86). The novel approach is based on delaying detection of idioms and reconstruction of code to the later phase (a middleend part). For this purpose, we use the LLVM optimizer and we implement this analysis as a new pass in this tool. According to experimental results, this new approach significantly outperforms the previous approach as well as the other commercial solutions.


2015 ◽  
Vol 12 (3) ◽  
pp. 1055-1078
Author(s):  
Milos Bogdanovic ◽  
Aleksandar Stanimirovic ◽  
Leonid Stoimenov

In this paper we will define and describe a novel approach for the development of context-driven Web Map solutions. Our approach relies on an architecture we define and present in this paper as an enhancement of GIS application interoperability platforms. The enhancement is performed through introduction of a specific architectural layer which enables the development of context-driven Web Map solutions. A novel architectural layer we introduce consists of two central components: Web Map Context Service and Context Proposal Service. These services take advantage of existing GeoNis framework for interoperability of GIS applications and enable users get appropriately visualized geospatial data depending on their Web map context. The novel architectural layer performs externalization of Web map contexts in separate files complaint to Web Map Context Documents specification. Web map context files are used as configuration files to configure map display elements for each user. Rendering capabilities are also delegated to the client side which simplifies server components and improves system performances. The enhanced platform is capable of adapting to different users? needs without changing its internal structure and improves the level Web Map solution usability. Also, in this paper we will present an implementation of the proposed architecture and services with purpose of demonstrating the ability of our proposal to apply the existing GIS application interoperability platform for different Web map contexts and styles for viewing maps.


Cellulose ◽  
2021 ◽  
Author(s):  
Marc P. Vocht ◽  
Ronald Beyer ◽  
Patricija Thomasic ◽  
Alexandra Müller ◽  
Antje Ota ◽  
...  

AbstractWe report on a new process for the spinning of high-performance cellulosic fibers. For the first time, cellulose has been dissolved in the ionic liquid (IL) 1-ethyl-3-methylimidazolium octanoate ([C2C1im][Oc]) via a thin film evaporator in a continuous process. Compared to other ILs, [C2C1im][Oc] shows no signs of hydrolysis with water. For dope preparation the degree of polymerization of the pulp was adjusted by electron beam irradiation and determined by viscosimetry. In addition, the quality of the pulp was evaluated by means of alkali resistance. Endless filament fibers have been spun using dry-jet wet spinning and an extruder instead of a spinning pump, which significantly increases productivity. By this approach, more than 1000 m of continuous multifilament fibers have been spun. The novel approach allows for preparing cellulose fibers with high Young's modulus (33 GPa) and unprecedented high tensile strengths up to 45 cN/tex. The high performance of the obtained fibers provides a promising outlook for their application as replacement material for rayon-based tire cord fibers.


Author(s):  
Mariane Beatriz Sordi ◽  
Ariadne Cristiane Cabral da Cruz ◽  
Águedo Aragones ◽  
Mabel Mariela Rodríguez Cordeiro ◽  
Ricardo de Souza Magini

The aim of this study was to synthesize, characterize, and evaluate degradation and biocompatibility of poly(lactic-co-glycolic acid) + hydroxyapatite / β-tricalcium phosphate (PLGA+HA/βTCP) scaffolds incorporating simvastatin (SIM) to verify if this biomaterial might be promising for bone tissue engineering. Samples were obtained by the solvent evaporation technique. Biphasic ceramic particles (70% HA, 30% βTCP) were added to PLGA in a ratio of 1:1. Samples with SIM received 1% (m:m) of this medication. Scaffolds were synthesized in a cylindric-shape and sterilized by ethylene oxide. For degradation analysis, samples were immersed in PBS at 37 °C under constant stirring for 7, 14, 21, and 28 days. Non-degraded samples were taken as reference. Mass variation, scanning electron microscopy, porosity analysis, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetry were performed to evaluate physico-chemical properties. Wettability and cytotoxicity tests were conducted to evaluate the biocompatibility. Microscopic images revealed the presence of macro, meso, and micropores in the polymer structure with HA/βTCP particles homogeneously dispersed. Chemical and thermal analyses presented very similar results for both PLGA+HA/βTCP and PLGA+HA/βTCP+SIM. The incorporation of simvastatin improved the hydrophilicity of scaffolds. Additionally, PLGA+HA/βTCP and PLGA+HA/βTCP+SIM scaffolds were biocompatible for osteoblasts and mesenchymal stem cells. In summary, PLGA+HA/βTCP scaffolds incorporating simvastatin presented adequate structural, chemical, thermal, and biological properties for bone tissue engineering.


2020 ◽  
Author(s):  
James McDonagh ◽  
William Swope ◽  
Richard L. Anderson ◽  
Michael Johnston ◽  
David J. Bray

Digitization offers significant opportunities for the formulated product industry to transform the way it works and develop new methods of business. R&D is one area of operation that is challenging to take advantage of these technologies due to its high level of domain specialisation and creativity but the benefits could be significant. Recent developments of base level technologies such as artificial intelligence (AI)/machine learning (ML), robotics and high performance computing (HPC), to name a few, present disruptive and transformative technologies which could offer new insights, discovery methods and enhanced chemical control when combined in a digital ecosystem of connectivity, distributive services and decentralisation. At the fundamental level, research in these technologies has shown that new physical and chemical insights can be gained, which in turn can augment experimental R&D approaches through physics-based chemical simulation, data driven models and hybrid approaches. In all of these cases, high quality data is required to build and validate models in addition to the skills and expertise to exploit such methods. In this article we give an overview of some of the digital technology demonstrators we have developed for formulated product R&D. We discuss the challenges in building and deploying these demonstrators.<br>


2020 ◽  
Author(s):  
Elaine Gallagher ◽  
Bas Verplanken ◽  
Ian Walker

Social norms have been shown to be an effective behaviour change mechanism across diverse behaviours, demonstrated from classical studies to more recent behaviour change research. Much of this research has focused on environmentally impactful actions. Social norms are typically utilised for behaviour change in social contexts, which facilitates the important element of the behaviour being visible to the referent group. This ensures that behaviours can be learned through observation and that deviations from the acceptable behaviour can be easily sanctioned or approved by the referent group. There has been little focus on how effective social norms are in private or non-social contexts, despite a multitude of environmentally impactful behaviours occurring in the home, for example. The current study took the novel approach to explore if private behaviours are important in the context of normative influence, and if the lack of a referent groups results in inaccurate normative perceptions and misguided behaviours. Findings demonstrated variance in normative perceptions of private behaviours, and that these misperceptions may influence behaviour. These behaviours are deemed to be more environmentally harmful, and respondents are less comfortable with these behaviours being visible to others, than non-private behaviours. The research reveals the importance of focusing on private behaviours, which have been largely overlooked in the normative influence literature.


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