Nature Nanocomposite Versus Man-Made Nanocomposites: Studies of Nanoscale Structural, Chemical and Mechanical Hierarchy of a Fish Scale in Contrast With Man-Made Polymer Nanocomposites

2013 ◽  
Author(s):  
D. Devaprakasam
Keyword(s):  
Mechanical Properties ◽  
Protective Layer ◽  
Living Organism ◽  
Sio2 Nanoparticles ◽  
Biological Properties ◽  
The Body ◽  
Dramatic Improvement ◽  
Fish Scale ◽  
Length Scales ◽  
Wide Range

Hierarchical designs of biological structures have remarkable physical, chemical mechanical and biological properties and functionalities over the wide range of length scales [1–4]. Man-made nanocomposites have dramatic improvement of the structural and mechanical properties but however they have very limited hierarchy [5]. Fish scales are bone-like tissues, which form a protective layer on the body of the fish and enable the fish to swim efficiently. Bones and bone-like parts in living organism are formed as tissues by self-assembly of bio-minerals and protein matrix. These tissues are bio-nanocomposites and have hierarchical structure ranging from nanoscale to macroscale [2–4]. Bio-hierarchy contains different bio-macromolecules, bio-minerals, interfacial bonds and porosity which result in gradient mechanical properties at multiple length scales [1–6]. Fish scale consists of inorganic bio-minerals and organic collagens [3,4]. Multilevel hierarchy influences elasticity, hardness and fracture toughness of fish scale. They have additional functions related to movement including reduction or increase of drag [7] and rapid manoeuvre while they are hunting or avoiding predators. In this article we report comparison studies of hierarchical nanocomposite of sardina pilchardus(sp) fish scale and man-made SiO2 nanoparticles filled nanocomposites.

Bioresorbable Composites and Implant

2019 ◽  
pp. 57-76
Author(s):  
Divya Zindani
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Degradation Rate ◽  
Clinical Applications ◽  
The Body ◽  
Metal Alloys ◽  
Medical Sciences ◽  
Intended Function ◽  
Wide Range ◽  
Modification Rate

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.

Bioresorbable Composites and Implant

2021 ◽  
pp. 443-456
Author(s):  
Divya Zindani
Keyword(s):  
Mechanical Properties ◽  
Surface Modification ◽  
Degradation Rate ◽  
Clinical Applications ◽  
The Body ◽  
Metal Alloys ◽  
Medical Sciences ◽  
Intended Function ◽  
Wide Range ◽  
Modification Rate

Different biomaterials in the form of ceramics, metal alloys, composites, glasses, polymers, etc. have gained wide-range acceptance in the realm of medical sciences. Bioimplants from such biomaterials have been constructed and used widely for different clinical applications. With the continual progress, biomaterials that may be resorbed inside the body have been developed. These have done away with the major challenge of removal of an implant after it has served its intended function. Important factors are taken into consideration in design and development of implants from such biomaterials are mechanical properties, degradation rate, surface modification, rate of corrosion, biocompatibility, and non-toxicity. Given the importance of such materials in clinical applications, the chapter presents an overview of the bioresorable composites and their implants. The related properties and the functions served have been outlined briefly. Further, the challenges associated and the remedies to overcome them have also been delineated.

scholarly journals Recent advances on the measurement and calculation of the elastic moduli of cortical and trabecular bone: A review

2011 ◽  
Vol 38 (3) ◽  
pp. 209-297 ◽  
Author(s):  
Ekaterina Novitskaya ◽  
Po-Yu Chen ◽  
Elham Hamed ◽  
Li Jun ◽  
Vlado Lubarda ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Trabecular Bone ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
The Body ◽  
Multifunctional Material ◽  
Recent Advances ◽  
Wide Range ◽  
Experimental Approaches ◽  
Open Issues

In this review, recent advances on the measurement and modeling of elastic properties of cortical and trabecular bone are presented. Bone is a multifunctional material which among its other functions serves as a support for other tissues in the body. As a structural material it is stiff, strong, tough, lightweight and is adaptable. Its excellent mechanical properties are due to its complex, composite and hierarchical structure. In this paper, we outline the experimental approaches that have been used to characterize bone?s structure, composition and elastic properties at several different length scales. Then, we discuss different modeling approaches that have been employed to compute bone?s elastic moduli. We conclude by discussing the challenges and open issues in this area. Analysis of bone is of importance in orthopedics. Also, gained knowledge on bone can be used by engineers to design new bioinspired composite materials for a wide range of engineering applications.

scholarly journals Candidate Polyurethanes Based on Castor Oil (Ricinus communis), with Polycaprolactone Diol and Chitosan Additions, for Use in Biomedical Applications

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 237 ◽  
Author(s):  
Yomaira Uscátegui ◽  
Luis Díaz ◽  
José Gómez-Tejedor ◽  
Ana Vallés-Lluch ◽  
Guillermo Vilariño-Feltrer ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Line ◽  
Castor Oil ◽  
Sessile Drop ◽  
Colorimetric Assay ◽  
Biological Properties ◽  
Wound Dressings ◽  
Cytotoxicity Test ◽  
Wide Range

Polyurethanes are widely used in the development of medical devices due to their biocompatibility, degradability, non-toxicity and chemical versatility. Polyurethanes were obtained from polyols derived from castor oil, and isophorone diisocyanate, with the incorporation of polycaprolactone-diol (15% w/w) and chitosan (3% w/w). The objective of this research was to evaluate the effect of the type of polyol and the incorporation of polycaprolactone-diol and chitosan on the mechanical and biological properties of the polyurethanes to identify the optimal ones for applications such as wound dressings or tissue engineering. Polyurethanes were characterized by stress-strain, contact angle by sessile drop method, thermogravimetric analysis, differential scanning calorimetry, water uptake and in vitro degradation by enzymatic processes. In vitro biological properties were evaluated by a 24 h cytotoxicity test using the colorimetric assay MTT and the LIVE/DEAD kit with cell line L-929 (mouse embryonic fibroblasts). In vitro evaluation of the possible inflammatory effect of polyurethane-based materials was evaluated by means of the expression of anti-inflammatory and proinflammatory cytokines expressed in a cellular model such as THP-1 cells by means of the MILLIPLEX® MAP kit. The modification of polyols derived from castor oil increases the mechanical properties of interest for a wide range of applications. The polyurethanes evaluated did not generate a cytotoxic effect on the evaluated cell line. The assessed polyurethanes are suggested as possible candidate biomaterials for wound dressings due to their improved mechanical properties and biocompatibility.

Overview of Enzyme Engineering Towards the Production of Hyaluronic Acid with Tailored Molecular Weight

2021 ◽  
Vol 23 ◽  
Author(s):  
Tahereh Ebrahimi ◽  
Kamran Hosseini ◽  
Hossein Ahangari ◽  
Pourya Gholizadeh ◽  
Vahideh Tarhriz
Keyword(s):  
Molecular Weight ◽  
Hyaluronic Acid ◽  
Critical Role ◽  
Biological Properties ◽  
Research Field ◽  
Enzyme Engineering ◽  
The Body ◽  
Synthesis Process ◽  
Hyaluronan Synthase ◽  
Wide Range

: Hyaluronic acid or hyaluronan (HA) is a natural biopolymer composed of D-glucuronic acid and N-acetylglucosamine units, distributed as a non-sulfated and anionic glycosaminoglycan in important tissues of the body, and is commercially and biologically important. Its biological properties are determined by the molecular weight and dispersity which are suitable for particular medical and cosmetic applications. The synthesis of well-defined and monodisperse HA is still a significant obstacle and an impressive research field for advanced medical applications. High polydispersity by bacterial fermentation, the lack of knowledge of the mechanism required to start and continue the synthesis process, increased cost of raw materials to produce HA, clarification and explanation of factors limiting synthesis in bacterial systems are among the important challenges of hyaluronic acid synthesis. Hyaluronan synthase plays a critical role in HA molecular mass by producing a wide range of HA involved in various biological processes. Hyaluronan biosynthesis has been considered extensively; however, the control of its size and weight during the synthesis process is poorly investigated. This review focuses on these uncharted biochemical details to obtain the uniform chain lengths of Hyaluronan by protein engineering and regulating the function of Hyaluronan synthase.

Anatomy and mechanical properties of woods used in electric guitars

IAWA Journal ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 106-S6 ◽  
Author(s):  
Patrik Ahvenainen
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Wood Species ◽  
Principal Component ◽  
High Density ◽  
The Body ◽  
Electric Guitar ◽  
Wide Range ◽  
Acoustic Instruments ◽  
Electric Guitars

ABSTRACT Many endangered tropical hardwoods are commonly used in electric guitars. In order to find alternative woods, the current electric guitar woods need to be studied and classified as most research in this field has focused on acoustic instruments. Classification was done based on luthier literature, woods used in commercially available electric guitars, commercially available tonewoods and by interviewing Finnish luthiers. Here, the electric guitar woods are divided into three distinct classes based on how they are used in the guitar: low-density wood used in the body only (alder, poplar, basswood, ash), medium-density wood used in the body and neck (maple and mahogany), and high-density wood used in the fretboard only (rosewood and ebony). Together, these three classes span a wide range of anatomical and mechanical properties, but each class itself is limited to a relatively narrow parameter space. Statistically significant differences between these classes and the average hardwoods exist in the wood anatomy (size and organization of vessels, fibres, rays and axial parenchyma), in the mechanical properties (density, elastic modulus, Janka hardness, etc.) and in the average price per volume. In order to find substitute woods for a certain guitar wood class, density and elastic modulus can already be used to rule out most wood species. Based on principal component analysis of the elastomechanical and anatomical properties of commercially available hardwoods, few species are similar to the low- and high-density class woods. However, for all of the three electric guitar wood classes, non-endangered wood species are already commercially available from tonewood retailers that match the class characteristics presented here.

scholarly journals Influence of Metallic Oxide Nanoparticles on the Mechanical Properties of an A-TIG Welded 304L Austenitic Stainless Steel

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4513
Author(s):  
Sebastian Balos ◽  
Miroslav Dramicanin ◽  
Petar Janjatovic ◽  
Nenad Kulundzic ◽  
Ivan Zabunov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Base Metal ◽  
Austenitic Stainless Steels ◽  
Sio2 Nanoparticles ◽  
Oxide Nanoparticles ◽  
Chemical Compositions ◽  
Metallic Oxide ◽  
Activating Flux ◽  
Wide Range ◽  
Metallic Oxide Nanoparticles

Austenitic stainless steels represent a significant aerospace material, being used for various castings, structural components, landing gear components, afterburners, exhaust components, engine parts, and fuel tanks. The most common joining process is tungsten inert gas (TIG) welding, which possesses many advantages such as suitability to weld a wide range of ferrous and non-ferrous metals and alloys, providing high quality welds with good mechanical properties. Its major disadvantage is low productivity due to low penetration and welding speed. This can be overcome by introducing an activating flux before welding. The activating flux reverses the material flow of the weld pool, significantly increasing penetration. Therefore, shielding gas consumption is reduced and welding without a consumable is enabled. However, the consumable in conventional TIG also enables the conditioning of the mechanical properties of welds. In this study, Si and Ti metallic oxide nanoparticles were used to increase the weld penetration depth, while bend testing, tensile, and impact toughness were determined to evaluate the mechanical properties of welds. Furthermore, optical emission spectroscopy, light, and scanning electron microscope were used to determine the chemical compositions and microstructures of the welds. Chemical compositions and weld mechanical properties were similar in all specimens. The highest tensile and impact properties were obtained with the specimen welded with the flux containing 20% TiO2 and 80% SiO2 nanoparticles. Although lower than those of the base metal, they were well within the nominal base metal mechanical properties.

Rola tłuszczu w żywieniu człowieka

2019 ◽  
Vol 22 (4) ◽  
Author(s):  
Magdalena Rudzińska ◽  
Roman Przybylski
Keyword(s):  
Unsaturated Fatty Acids ◽  
Large Body ◽  
Calorific Value ◽  
Fats And Oils ◽  
Biological Properties ◽  
The Body ◽  
Dietary Fats ◽  
Human Diet ◽  
Wide Range

Along with proteins and carbohydrates, fat is one of the three most important components of the human diet. For years, it was recommended that the intake of fats should be as low as possible due to their high calorific value. It is currently assumed that 30-35% of dietary energy should come from fat as it is a source of many bioactive compounds, such as essential unsaturated fatty acids (EUFAs), antioxidants and vitamins (A, D, E, K), which must be delivered to the body with food. Their content in vegetable fats and oils varies greatly, and the existing consumer opinions and beliefs often contradict scientific knowledge. Currently, a large body of evidence supporting the important role of fats in the human diet may be found in literature. This paper discusses the basic components of vegetable fats and oils in terms of their chemical structure and biological properties. A wide range of dietary fats were reviewed for their fatty acid, tocopherol and sterol profiles. Based on these facts, criteria to be taken into account in the selection of dietary fats and food products were identified.

scholarly journals Differences in Steap3 expression are a mechanism of genetic variation of RBC storage and oxidative damage in mice

2019 ◽  
Vol 3 (15) ◽  
pp. 2272-2285 ◽  
Author(s):  
Heather L. Howie ◽  
Ariel M. Hay ◽  
Karen de Wolski ◽  
Hayley Waterman ◽  
Jenna Lebedev ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Oxidative Damage ◽  
Cellular Membrane ◽  
Biological Properties ◽  
Substantial Effect ◽  
The Body ◽  
Redox Biology ◽  
Wide Range ◽  
Different Strains

Abstract Red blood cells (RBCs) are the most numerous cell type in the body and serve a vital purpose of delivering oxygen to essentially all tissues. In addition to the central role of RBCs in health and disease, RBC storage is a requirement for the >90 million units of RBC transfusions given to millions of recipients each year, worldwide. It is well known that there is genetic donor-to-donor variability in how human RBCs store, rendering blood a nonstandardized therapeutic with a wide range of biological properties from unit to unit, by the time it is transfused. As with humans, genetic variation exists in how murine RBCs, from different strains of mice, store and perform after transfusion. The genetic mechanisms for variation, in humans and mice, both remain obscure. Combining advanced metabolomics, genetics, and molecular and cellular biology approaches, we identify genetic variation in six-transmembrane epithelial antigen of prostate 3 (Steap3) expression as a critical and previously unrecognized mechanism of oxidative damage of RBCs during storage. Increased levels of Steap3 result in degradation of cellular membrane through lipid peroxidation, leading to failure of RBC homeostasis and hemolysis/clearance of RBCs. This article is the first report of a role of Steap3 in mature RBCs; it defines a new mechanism of redox biology in RBCs with a substantial effect upon RBC function and provides a novel mechanistic determinant of genetic variation of RBC storage.

Biological and mechanical evaluation of mineralized-hydrogel scaffolds for tissue engineering applications

2021 ◽  
pp. 088532822199542
Author(s):  
Aitor Tejo-Otero ◽  
Alastair C Ritchie
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Biological Properties ◽  
Hydrogel Scaffolds ◽  
Wide Range ◽  
Calcium Minerals ◽  
The One ◽  
Calcium Compounds ◽  
Cell Adhesion And Proliferation

Chitosan and gelatin have been extensively used in tissue engineering for a wide range of different applications, such as wound healing or bone regeneration, due to their advantages: excellent biocompatibility (promoting cell adhesion and proliferation), low price and biodegradability. Nonetheless, their main drawback is that they have poor mechanical properties, consequently restricting their use in bone tissue engineering. In previous studies, both materials were cross-linked, with added calcium minerals, which led to an improvement in both mechanical and biological properties. Therefore, this study carries out a mechanical and biological characterization of mineral-hydrogel scaffolds in order to find the best compositions. Different proportions of calcium compounds (CaCO3 and CaHPO4) are used to make up between 20% and 30% of the minerals used in a mineral-hydrogel mix. This addition of minerals enhances not only the mechanical properties, but also the biological ones. On the one hand, the higher the amount of minerals added to the composition, the better the mechanical properties obtained. Additionally, as the proportion of CaCO3 in comparison with CaHPO4 rises, the mechanical properties improve. On the other hand, both cell proliferation and mineralization are improved with the addition of calcium minerals.

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