다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

Large-Scale Fabrication of Boron Nitride Nanosheets and Their Utilization in Polymeric Composites with Improved Thermal and Mechanical Properties

Bone biomaterials play a vital role in bone repair by providing the necessary substrate for cell adhesion, proliferation, and differentiation and by modulating cell activity and function. In past decades, extensive efforts have been devoted to developing bone biomaterials with a focus on the following issues: (1) developing ideal biomaterials with a combination of suitable biological and mechanical properties; (2) constructing a cell microenvironment with pores ranging in size from nanoscale to submicro- and microscale; and (3) inducing the oriented differentiation of stem cells for artificial-to-biological transformation. Here we present a comprehensive review of the state of the art of bone biomaterials and their interactions with stem cells. Typical bone biomaterials that have been developed, including bioactive ceramics, biodegradable polymers, and biodegradable metals, are reviewed, with an emphasis on their characteristics and applications. The necessary porous structure of bone biomaterials for the cell microenvironment is discussed, along with the corresponding fabrication methods. Additionally, the promising seed stem cells for bone repair are summarized, and their interaction mechanisms with bone biomaterials are discussed in detail. Special attention has been paid to the signaling pathways involved in the focal adhesion and osteogenic differentiation of stem cells on bone biomaterials. Finally, achievements regarding bone biomaterials are summarized, and future research directions are proposed.

/pdf/bone-biomaterials-and-interactions-with-stem-cells-4c9eg43ssz.pdf

Bone biomaterials and interactions with stem cells.

Extensive research on two-dimensional (2D) materials has triggered the renaissance of an old topic, that is, the intercalation and exfoliation of layer materials. Such top-down exfoliation produced 2D materials and their dispersions have several advantages including low cost, scalable production capability, solution processability, and versatile functionalities stemming from the large number of species of layer materials, and show promising potential in many applications. In recent years, many new methods have been developed for exfoliating layer materials to 2D materials for different application purposes. In this review the different exfoliation approaches are first systematically analyzed from the viewpoint of methodology, and the advantages and disadvantages of each method are compared. Second, the assembly of exfoliated 2D materials into macrostructures by solution-based techniques is summarized. Third, the state-of-the-art applications of 2D material dispersions and their assemblies in electronics and optoelectronics, electrocatalysis, energy storage, etc., are discussed. Finally, insights and perspectives on current research challenges and future opportunities regarding the exfoliation and applications of 2D materials in dispersions are considered.

Preparation of 2D material dispersions and their applications

Graphene based materials have attracted great interest in the development of new and advanced protective coatings due to their excellent chemical resistance, impermeability to gases, adsorption capacity, anti-bacterial properties, mechanical strength, lubricity and thermal stability. This review presents current progress and discusses the major challenges and future potential of graphene in the field of protective coatings. This review specifically focuses on the most recent advances in the application of graphene for corrosion resistant coatings, flame retardant coatings, wear/scratch resistant coatings, anti-fouling coatings, pollutant adsorption coatings and anti-septic coatings.

Graphene: a multipurpose material for protective coatings

https://iopscience.iop.org/article/10.1088/1468-6996/15/1/014402/pdf

Effects of surface coating on reducing friction and wear of orthopaedic implants

Superhydrophobic surfaces for self-cleaning applications often suffer from mechanical instability and do not function well after abrasion/scratching. To address this problem, we present a method to prepare graphene-based superhydrophobic composite coatings with robust mechanical strength, self-cleaning, and barrier properties. A suspension has been formulated that contains a mixture of reduced graphene oxide (rGO) and diatomaceous earth (DE) modified with polydimethylsiloxane (PDMS) that can be applied on any surface using common coating methods such as spraying, brush painting, and dip coating. Inclusion of TiO2 nanoparticles to the formulation shows further increase in water contact angle (WCA) from 159 ± 2° to 170 ± 2° due to the structural improvement with hierarchical surface roughness. Mechanical stability and durability of the coatings has been achieved by using a commercial adhesive to bond the superhydrophobic “paint” to various substrates. Excellent retention of superhydrophobicity was observed ...

Robust Superhydrophobic Graphene-Based Composite Coatings with Self-Cleaning and Corrosion Barrier Properties

Development of next-generation sensor devices is gaining tremendous attention in both academia and industry because of their broad applications in manufacturing processes, food and environment control, medicine, disease diagnostics, security and defense, aerospace, and so forth. Current challenges include the development of low-cost, ultrahigh, and user-friendly sensors, which have high selectivity, fast response and recovery times, and small dimensions. The critical demands of these new sensors are typically associated with advanced nanoscale sensing materials. Among them, graphene and its derivatives have demonstrated the ideal properties to overcome these challenges and have merged as one of the most popular sensing platforms for diverse applications. A broad range of graphene assemblies with different architectures, morphologies, and scales (from nano-, micro-, to macrosize) have been explored in recent years for designing new high-performing sensing devices. Herein, this study presents and discusses recent advances in synthesis strategies of assembled graphene-based superstructures of 1D, 2D, and 3D macroscopic shapes in the forms of fibers, thin films, and foams/aerogels. The fabricated state-of-the-art applications of these materials in gas and vapor, biomedical, piezoresistive strain and pressure, heavy metal ion, and temperature sensors are also systematically reviewed and discussed, and their sensing performance is compared.

Recent Advances in Sensing Applications of Graphene Assemblies and Their Composites

Wear debris, of deferent sizes, shapes and quantities, generated in artificial hip and knees is largely confined to the bone and joint interface. This debris interacts with periprosthetic tissue and may cause aseptic loosening. The purpose of this review is to summarize and collate findings of the recent demonstrations on debris characterization and their biological response that influences the occurrence in implant migration. A systematic review of peer-reviewed literature is performed, based on inclusion and exclusion criteria addressing mainly debris isolation, characterization, and biologic responses. Results show that debris characterization largely depends on their appropriate and accurate isolation protocol. The particles are found to be non-uniform in size and non-homogeneously distributed into the periprosthetic tissues. In addition, the sizes, shapes, and volumes of the particles are influenced by the types of joints, bearing geometry, material combination, and lubricant. Phagocytosis of wear debris is size dependent; high doses of submicron-sized particles induce significant level of secretion of bone resorbing factors. However, articles on wear debris from engineered surfaces (patterned and coated) are lacking. The findings suggest considering debris morphology as an important parameter to evaluate joint simulator and newly developed implant materials.

/pdf/wear-debris-characterization-and-corresponding-biological-xfe5xocv62.pdf

J. Nine

Papers

Graphene: a multipurpose material for protective coatings

Effects of surface coating on reducing friction and wear of orthopaedic implants

Robust Superhydrophobic Graphene-Based Composite Coatings with Self-Cleaning and Corrosion Barrier Properties

Recent Advances in Sensing Applications of Graphene Assemblies and Their Composites

Wear Debris Characterization and Corresponding Biological Response: Artificial Hip and Knee Joints.