Variety Of Novel Materials Research Articles

Reviewing dental materials: Progresses for oral health and restoration

The field of density has made great progress in the modern era, especially in the aspects of developing a variety of novel materials that are used to repair teeth. Compared to traditional c, novel dental restorative materials are devoted to combining practicality and aesthetics, which are under the full consideration of the demands of patients. The emphasis of this review lies in the comparison of different novel dental restorative materials by providing their principles, benefits, disadvantages, and applications. The main advanced materials in this area that are chosen to be researched in this review are Ultra-High Molecular Weight Polyethylene Nanocomposites, Zirconia-based Composites, Activa Bioactive Restorative, Hydroxyapatite Restoration Materials, Bioprinting Materials, as well as Biomimetic and Tooth Surface Regeneration Materials. Researchers need to innovate in dental restorative materials with continuous pursuit. As these novel materials rapidly develop and are taken actions into application, they have a positive influence on dentistry. Our work involving studies of novel dental restorative materials provides patients with more practical and aesthetic therapy suggestions.

Stereocomplexed Materials of Chiral Polymers Tuned by Crystallization: A Case Study on Poly(lactic acid)

ConspectusWidespread in chemistry and biochemistry, chirality strongly affects the biological, chemical, material, and physical properties. As a downstream derivative, the enantiopure polymers of opposite chirality can cocrystallize in the stereocomplex (SC) in their enantiomeric blends or block copolymers, which endows the materials with improved physical properties and specific functions such as enhanced melting temperature, thermal stability, crystallizability, and hydrolytic resistance. A well-studied stereocomplexable polymer is poly(lactic acid) (PLA); both of its two enantiomers, poly(l-lactic acid) and poly(d-lactic acid), are biobased and biodegradable. SC crystallization is a simple and practical approach to improve the essential properties and functions of chiral polymers, which advances existing polymer applications and paves a new way to develop a variety of novel materials. However, it is noteworthy that not all of the enantiomeric blends of l- and d-polymers can exclusively crystallize into SC crystals in a typical crystallization process, which is usually accompanied by the homocrystallization of each individual enantiomer. Developing stereocomplexed materials with controlled crystalline structure, physical properties, and functions is still challenging. Consequently, studying and discussing the stereocomplexed materials developed by harnessing SC crystallization are of fundamental importance not only to obtain novel functional materials but also to promote the advancement of material researches.In this Account, we concisely summarize and analyze our recent progresses in SC crystallization and stereocomplexed materials of PLA, which initializes a conceptual methodology to study and develop the stereocomplexed materials from chiral polymers. We first introduce various approaches for controlling the polymorphic crystallization structure, in order to promote the SC crystallization of high-molecular-weight PLA and to prepare the stereocomplexed materials. Then, we present our efforts on the preparation of novel stereocomplexed materials such as micelles, physical hydrogels, and elastomers by harnessing SC crystallization. These stereocomplexed materials show good physical properties (e.g., thermomechanical property and thermal resistance) and can further be functionalized toward shape memory, drug release, and thermoresponsive materials. These works have established a practical platform to unveil the relationships between crystalline structure, physical properties, and functions of stereocomplexed materials. At the end of the Account, we offer a brief summary and outlooks in this field. Even though a case study on PLA is focused in this Account, a similar methodology can be generalizable to other chiral polymer systems. We hope that this Account will evoke new inspirations and innovative work in the field of stereocomplexed materials of chiral polymers in the near future.

PH-Stat Titration: A Rapid Assay for Enzymatic Degradability of Bio-Based Polymers.

Bio-based polymers have been suggested as one possible opportunity to counteract the progressive accumulation of microplastics in the environments. The gradual substitution of conventional plastics by bio-based polymers bears a variety of novel materials. The application of bioplastics is determined by their stability and bio-degradability, respectively. With the increasing implementation of bio-based plastics, there is also a demand for rapid and non-elaborate methods to determine their bio-degradability. Here, we propose an improved pH Stat titration assay optimized for bio-based polymers under environmental conditions and controlled temperature. Exemplarily, suspensions of poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) microparticles were incubated with proteolytic and lipolytic enzymes. The rate of hydrolysis, as determined by counter-titration with a diluted base (NaOH), was recorded for two hours. PLA was hydrolyzed by proteolytic enzymes but not by lipase. PBS, in contrast, showed higher hydrolysis rates with lipase than with proteases. The thermal profile of PLA hydrolysis by protease showed an exponential increase from 4 to 30 °C with a temperature quotient Q10 of 5.6. The activation energy was 110 kJ·mol−1. pH-Stat titration proved to be a rapid, sensitive, and reliable procedure supplementing established methods of determining the bio-degradability of polymers under environmental conditions.

Zero Crossing Steps and Anomalous Shapiro Maps in Graphene Josephson Junctions.

The AC Josephson effect manifests itself in the form of "Shapiro steps" of quantized voltage in Josephson junctions subject to radiofrequency (RF) radiation. This effect presents an early example of a driven-dissipative quantum phenomenon and is presently utilized in primary voltage standards. Shapiro steps have also become one of the standard tools to probe junctions made in a variety of novel materials. Here we study Shapiro steps in a widely tunable graphene-based Josephson junction in which the high-frequency dynamics is determined by the on-chip environment. We investigate the variety of patterns that can be obtained in this well-understood system depending on the carrier density, temperature, RF frequency, and magnetic field. Although the patterns of Shapiro steps can change drastically when just one parameter is varied, the overall trends can be understood and the behaviors straightforwardly simulated, showing some key differences from the conventional RCSJ model. The resulting understanding may help interpret similar measurements in more complex materials.

3D printing of acellular scaffolds for bone defect regeneration: A review

Bone injuries can be treated using tissue engineering scaffolds, but the conventional constructs have a big challenge in supplying requirements of native tissue, i.e., bioactivity potential, mechanical stability, controllable biodegradability, and proper cellular interaction. In this regard, 3D printing technology with the possibility of controlling the internal microstructure and geometry of synthesized matrixes was introduced as a promising approach for bone defect regeneration. Although a variety of novel materials, which have shown initial potential for bone repair, can be used for preparing the biocompatible matrixes, the 3D printer type and selecting an innovated technology depend on the properties of applied biomaterials. In all the used methods, tunable, controllable, and interconnected porous microstructure can be fabricated even though identification of suitable porosity and microstructure, which can supply required mechanical properties of natural bone and support cellular adhesion, proliferation, and differentiation, need to evaluate. Therefore, this mini-review explains current advances in acellular 3D printed scaffolds, proper microporous structure and geometry for bone repair, and suitable materials for 3D printing the regenerative bone substitutes. Herein, the novel and recent studies were focused and probable limitations, and existing strategies were discussed.

Extracting Atomic Defect Properties From Leakage Current Temperature Dependence

In modern electronic devices, a variety of novel materials have been introduced such as transition metal oxides, chalcogenides, ferroelectric, and magnetic materials. The electrical response of such materials, used also as active layers, is strongly affected by atomic defects, which affect device performances, variability, and reliability. Extracting the defect properties (i.e., density, energy, and atomic nature) is, thus, crucial to both engineer the performances of electron devices and correctly project their scaling potential and reliability. In this paper, we propose a simple method to extract the atomic properties of defects from the thermal activation energy of the leakage current using a charge trapping relaxation model.

C3a/C3aR axis confers the protection against urinary tract infection

Development of biomimetic and instructive materials is emerging as a promising approach for redirecting fibrotic wound healing into a regenerative process. In nature, complete tissue regeneration can transpire in certain organ substructures, during embryogenesis and, remarkably, in some organisms in which whole limbs can regrow. These regenerative phenomena were observed to possess specific extracellular matrices, as well as stem cell niches and regulatory signaling pathways, that likely act as spatiotemporal organizers of these preferred outcomes. Biomimetic materials are now improving on the limitations of existing wound care treatments because they are being designed to stimulate these spatiotemporal cues, thus supporting regeneration within host tissues. A variety of novel materials have already emerged and demonstrated promise both in preclinical studies and in patients. This review discusses the recent advances in understanding these biomimetic and instructive properties and their integration into wound care scaffolds.

Electrophoretic Deposition of Gelatin/Hydroxyapatite Composite Coatings onto a Stainless Steel Substrate

Biodegradable polymers and bioactive ceramics are being combined in a variety of novel materials for tissue engineering scaffolds. These composite systems, which combine the useful mechanical properties of polymers with the bioactivity of ceramics, seem to be a promising choice for bone tissue engineering. In recent years, the use of biopolymers that gelate on cooling has received a lot of attention with regards to the production of laminates and coatings. In this work, we report the incorporation of hydroxyapatite (HA) into a gelatin coating on stainless steel substrate using colloidal processing technology. A titania (Ti) buffer layer prepared by dip coating was inserted to improve the bonding strength between the HA/gelatin layer and stainless steel substrate. The suspensions, composed of 1 vol% of HA and three different additions of gelatin, were formulated with a focus on rheological properties for codeposition of both phases by electrophoretic deposition (EPD). The composite coatings performed by EPD were investigated in terms of deposition efficiency and kinetics over different deposition times. The EPD process was performed at both ambient temperature and the gelling temperature of the suspension. While at room temperature no electrophoretic growth of the layers was observed, the thermal gelation of gelatin promotes the growth of a homogeneous, well-adherent coating.

The Concentration-Dependent Distribution of Tris(4,7'-diphenyl-1,10'-phenanthroline) Ruthenium (II) within Sol-Gel-Derived Thin Films

distributionwithin the xerogel.Key Words : Ru(II) dopant, Sol-gel, Luminescence, Optical sensorIntroductionSol-gel processing is an attractive method that can be usedto prepare a variety of novel materials that contain a widerange of active dopants (e.g., catalysts, chromophores,recognition chemistries, and proteins).

Many-body interactions in quasi-freestanding graphene

The Landau-Fermi liquid picture for quasiparticles assumes that charge carriers are dressed by many-body interactions, forming one of the fundamental theories of solids. Whether this picture still holds for a semimetal such as graphene at the neutrality point, i.e., when the chemical potential coincides with the Dirac point energy, is one of the long-standing puzzles in this field. Here we present such a study in quasi-freestanding graphene by using high-resolution angle-resolved photoemission spectroscopy. We see the electron-electron and electron-phonon interactions go through substantial changes when the semimetallic regime is approached, including renormalizations due to strong electron-electron interactions with similarities to marginal Fermi liquid behavior. These findings set a new benchmark in our understanding of many-body physics in graphene and a variety of novel materials with Dirac fermions.

Graphene Oxide, Highly Reduced Graphene Oxide, and Graphene: Versatile Building Blocks for Carbon‐Based Materials

Isolated graphene, a nanometer-thick two-dimensional analog of fullerenes and carbon nanotubes, has recently sparked great excitement in the scientific community given its excellent mechanical and electronic properties. Particularly attractive is the availability of bulk quantities of graphene as both colloidal dispersions and powders, which enables the facile fabrication of many carbon-based materials. The fact that such large amounts of graphene are most easily produced via the reduction of graphene oxide--oxygenated graphene sheets covered with epoxy, hydroxyl, and carboxyl groups--offers tremendous opportunities for access to functionalized graphene-based materials. Both graphene oxide and graphene can be processed into a wide variety of novel materials with distinctly different morphological features, where the carbonaceous nanosheets can serve as either the sole component, as in papers and thin films, or as fillers in polymer and/or inorganic nanocomposites. This Review summarizes techniques for preparing such advanced materials via stable graphene oxide, highly reduced graphene oxide, and graphene dispersions in aqueous and organic media. The excellent mechanical and electronic properties of the resulting materials are highlighted with a forward outlook on their applications.

Thermal Barrier Coatings Made by the Solution Precursor Plasma Spray Process

The solution precursor plasma spray (SPPS) process is a relatively new and flexible thermal spray process that can produce a wide variety of novel materials, including some with superior properties. The SPPS process involves injecting atomized droplets of a precursor solution into the plasma. The properties of resultant deposits depend on the time-temperature history of the droplets in the plasma, ranging from ultra-fine splats to unmelted crystalline particles to unpyrolized particles. By controlling the volume fraction of these three different constituents, a variety of coatings can be produced, all with a nanograin size. In this article, we will be reviewing research related to thermal barrier coatings, emphasizing the processing conditions necessary to obtain a range of microstructures and associated properties. The SPPS process produces a unique strain-tolerant, low-thermal conductivity microstructure consisting of (i) three-dimensional micrometer and nanometer pores, (ii) through-coating thickness (vertical) cracks, (iii) ultra-fine splats, and (iv) inter-pass boundaries. Both thin (0.12 mm) and thick (4 mm) coatings have been fabricated. The volume fraction of porosity can be varied from 10% to 40% while retaining the characteristic microstructure of vertical cracks and ultra-fine splats. The mechanism of vertical crack formation will be described.