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Injury to the facial nerve can occur after different etiologies and range from simple transection of the branches to varying degrees of segmental loss. Management depends on the extent of injury and options include primary repair for simple transections and using autografts, allografts, or conduits for larger gaps. Tissue engineering plays an important role to create artificial materials that are able to mimic the nerve itself without extra morbidity in the patients. The use of neurotrophic factors or stem cells inside the conduits or around the repair site is being increasingly studied to enhance neural recovery to a greater extent. Preclinical studies remain the hallmark for development of these novel approaches and translation into clinical practice. This review will focus on preclinical models of repair after facial nerve injury to help researchers establish an appropriate model to quantify recovery and analyze functional outcomes. Different bioengineered materials, including conduits and nerve grafts, will be discussed based on the experimental animals that were used and the defects introduced. Future directions to extend the applications of processed nerve allografts, bioengineered conduits, and cues inside the conduits to induce neural recovery after facial nerve injury will be highlighted. IMPACT STATEMENT: Recovery after facial nerve injury is a complex process, which involves different management options such as primary repair or the use of nerve grafts or conduits. Various tissue-engineered approaches are increasingly studied on preclinical models with limited, but promising, translation to the clinical setting. Herein, preclinical models focusing on different recovery methods after facial nerve injury are comprehensively reviewed based on the experimental animals used. The review provides key insights into current developments and future directions on this highly relevant topic to help researchers further expand the field of tissue engineering and facial nerve recovery.

Objective To summarize experience in the treatment of pentalogy of Cantrell (POC) in our hospital and explore the effect of artificial materials in repairing sternal defects. Materials and Methods A retrospective analysis was performed on treatment of five children with POC treated by using the Gore-Tex patch and titanium mesh in the Department of Cardio-Thoracic Surgery, Children's Hospital of Chongqing Medical University, from January 2010 to January 2019. Results The concurrent conditions included double outlet of right ventricle (n = 2), ventricular septal defect (VSD) and atrial septal defect (ASD) (n = 1), VSD and ASD and patent ductus arteriosus (n = 1), and VSD and left ventricular diverticulum (n = 1) in five cases with POC. Color Doppler echocardiography and computed tomography (CT) + three-dimensional (3D) reconstruction of the thorax and abdomen were performed preoperatively. The cardiac malformation was corrected according to color Doppler echocardiography, and a Gore-Tex patch was used to repair the pericardial defect. Titanium mesh was made according to CT 3D reconstruction with a 3D printing mold to repair sternal defects. All patients underwent a one-stage operation, all hearts were eventually repositioned, no deaths occurred after the operation, and follow-up was performed for 6 months to 2 years. The patients recovered well, and the exterior thorax was normal. Conclusion The diagnosis of POC is not difficult. The priority of surgical treatment for POC is to obtain satisfactory corrections of cardiac malformation. The repair of the pericardial defect with the Gore-Tex patch and the sternal defect with the titanium mesh can make the heart return to the mediastinum, reduce the pressure on the heart, reduce the surgical trauma, reduce the difficulty of repairing the sternal defect, and optimally restore the exterior thorax.

Total hip arthroplasty (THA) is one of the most successful surgical procedures. It entails replacement of the damaged or diseased joint surface with artificial materials. Various materials had been developed and used to achieve optimal outcomes, including longer survivorship and minimal complications. The primary materials used in the manufacture of THA implants are polymers, metal alloys, and ceramics. The failures of THA mainly result from aseptic loosening due to the production of wear particles and the development of periprosthetic joint injection. A lot of advancement and introduction of new biomaterials in THA implants’ armamentarium are designed to avoid the common failure mechanisms and improve the longevity of the implants. In this review, we discussed various aspects of commonly used biomaterials in THA implants, to provide some updated information.

This chapter introduces four types of advanced reconfigurable leaky‐wave antenna (LWA) structures for fixed‐frequency beam scanning, i.e., a reconfigurable Fabry–Perot LWA, a period‐reconfigurable substrate‐integrated‐waveguide LWA, a reconfigurable composite right‐/left‐handed LWA, and a uniplanar two‐dimensional multi‐beam LWA suited for millimeter‐wave operations. These antenna configurations and their operating mechanisms and performance are described. A way to produce a full‐range scanning LWA is through the introduction of metamaterial constructs, i.e., artificial materials with exotic properties that can be tailored to a given application. The two‐dimensional multi‐beam antenna presented divides the problem of generating 2‐D multi‐beams into two independent, one‐dimensional beamforming pieces. This topology makes it possible to have a flat uniplanar structure. Some future directions of research in reconfigurable LWAs are discussed to conclude the chapter.

This paper examines the influence of authentic materials on the motivation of the Faculty of Social Sciences, Kuwait University. The target population is male and female students of two intermediate levels at the Faculty of Social Sciences, Kuwait University. All students received both artificial and authentic materials. Data from two observation sheets as well as self-report questionnaires showed that on-task behavior and observed motivation increased when authentic materials were used, but selfreported motivation increased for all classes only in the last two to three weeks of the experiment. On the other hand, students believe that artificial materials are more enjoyable than authentic materials. The result of this experiment generally found that artificial materials are more interesting than authentic materials.

There is a need for an eco-friendly in situ reversible permeability control that reduces the number of artificial materials used to achieve a saturated sand layer. This study investigates such a control using a method that causes calcite precipitation and decalcification based on the metabolism of carbon sources. This generates carbon dioxide and organic acid and creates and detaches a biofilm using dry yeast and sodium hypochlorite. A pilot test determined the optimal chemical composition for this from a few different concentrations of carbon sources that begin the permeability reduction and recovery process. Following this, the main test (the permeability test) was conducted on a water sample taken from an agricultural area, which was combined with chemicals and dry yeast in a permeameter column. Permeability tests were carried out under three conditions (untreated, treated and treated combined with a biofilm detachment phase). The results suggest that (a) calcite precipitation induced by microbes, combined with bioclogging, can control the reduction in soil permeability and (b) a biofilm remover (sodium hypochlorite) and decalcification based on the organic acid created from the metabolism of carbon sources effectively recover the soil permeability to its initial state.

A review of modern literature on the development of biocompatible implants based on modern technologies, including bioengineering and nanostructuring, is presented. The advantages and disadvantages of implants based on metals and alloy, ways of improving their biological and mechanical properties are shown. In connection with the rapid development of many branches of science and technology, as well as in medicine, the problem arose of obtaining new materials, in particular, alloys with valuable physicochemical properties, which are used for the implant of cardiology, traumatology, orthopedics and other industries. Study of biocompatibility of medical devices based on metals and alloys, search for ways to overcome the low engraftability of implanted structures.

This article extends the concept of the term ‘material culture’ and addresses the production and use of artificial materials and imitative techniques as a phenomenon, defined here as ‘Imitative Mat...

Nanotechnology is an indispensable item in advanced bio-related and life sciences, but a novel concept is necessary to bridge the gaps between nanotechnology and biology/materials chemistry. The most suitable concept for this task would be nanoarchitectonics. In this short review article, our recent accomplishments of nanoarchitectonics approaches in cell functions including gene delivery and controlled differentiation are summarized. Regulation of cell activities by nanoarchitected materials is carried out through their interfacial contacts. Our accomplishments are here described according to the types of material structural motif, (i) nanotopography, (ii) self-assembled structures, and (iii) composite materials. Finally, several challenging approaches are introduced as frontiers of cell fate regulation at interfacial media. Development of artificial materials and systems to regulate bio-organization including living cells will give intuition and ideas even for the design of general functional systems. Interfacial nanoarchitectonics could be an important key concept for future advanced life technologies as well as currently required biomedical applications.

Living systems are built of multiscale-composites: materials formed of components with different properties that are assembled in complex micro- and nano-structures. Such biological multiscale-composites often show outstanding physical properties that are unachieved by artificial materials. A major scientific goal is thus to understand the assembly processes and the relationship between structure and function in order to reproduce them in a new generation of biomimetic high-performance materials. Here, we tested how the assembly of spider silk nano-fibres (i.e. glue coated 0.5 μm thick fibres produced by so-called piriform glands) into different micro-structures correlates with mechanical performance by empirically and numerically exploring the mechanical behaviour of line anchors in an orb weaver, a hunting spider and two ancient web builders. We demonstrate that the anchors of orb weavers exhibit outstanding mechanical robustness with minimal material use by the indirect attachment of the silk line to the substrate through a soft domain (‘bridge’). This principle can be used to design new artificial high-performance attachment systems.

Natural materials have always attracted intensive attention from multidisciplinary scientists all over the world. In fact, the ingenious and reasonable synthetic strategies of the limited components can always make natural materials achieve a superior performance that is far beyond their own. Meanwhile, the local properties can determine the overall performance through regulating multiple characteristics, including structure, composition, and interface. Living organisms can inspire the fabrication of artificial materials, which provides a clear vision for advanced materials research. Therefore, inspired by this strategy, biomimetic structural materials are used to meet the strict and even extreme requirements of engineering materials. In this review, we mainly clarify the difference of local properties in natural materials and explain how living organisms utilize very limited elements and compounds to control the local properties and further realize some specific function to adapt to the specific requirement of the environment. In addition, the manufacturing technologies and strategies common to bio-inspired structural materials are summarized. Finally, a summary and prospects on the limitations of current techniques and the direction of future developments for the design of novel bio-inspired materials are given.

The design of modular, passive, and static artificial metasurfaces to be used as electromagnetic skins (EMSs) of buildings for improving the coverage in urban millimeter-wave communication scenarios is addressed. Towards this end, an ad-hoc design strategy is presented to determine optimal trade-off implementative solutions that assure a suitable coverage of the areas of interest, where the signal from the base station is too weak, with the minimum complexity. More specifically, the admissible surface in the building facade is first partitioned into tiles, which are the minimum-size elements of the artificial coating (i.e., the building block of an EMS). Then, the search for the optimal EMS layout (i.e., the minimum number and the positions of the tiles to be installed) is carried out with a binary multi-objective optimization method. Representative numerical results are reported and discussed to point out the features and the potentialities of the EMS solution in the smart electromagnetic environment (SEME) as well as the effectiveness of the proposed design method.

The brick-and-mortar microstructure of nacre is usually considered as a source of inspiration for the development of strong and tough artificial materials. In this article, a nacre-inspired layered-and-staggered structural building ceramic protective covering was fabricated, and the effect of four types of adhesive materials on the ballistic performance of the protective covering was investigated through the ballistic test. The experimental results showed that under the impact of the 7.62-mm ordinary rifle bullet at a speed of 790–820 m/s, the average crater diameter in the concrete targets with protective covering was reduced by 40%–72%, and the penetration depth in the concrete was reduced by 70%–100%, compared with those of unprotected concrete targets. For the concrete targets with protective covering, that adopting the silicone sealant interlayers exhibited a smaller crater area but a maximum penetration depth, while that adopting the epoxy adhesive interlayers showed a larger crater area but a minimum penetration depth. Since the targets with the low-cost polyurethane sealant interlayers presented the smallest crater area and the shallower penetration depth, it can be concluded that the concrete with the protective covering using polyurethane sealant interlayers showed the better projectile impact resistance.

Fluorescent materials can shift energy between wavelengths, thereby creating bright and saturated colors both in natural and artificial materials. However, rendering fluorescence for continuous wavelengths or combined with wavelength dependent path configurations so far has only been feasible using spectral unidirectional methods. We present a regularization-based approach for supporting fluorescence in a spectral bidirectional path tracer. Our algorithm samples camera and light sub-paths with independent wavelengths, and when connecting them mollifies the BSDF at one of the connecting vertices such that it reradiates light across multiple wavelengths. We discuss arising issues such as color bias in early iterations, consistency of the method and MIS weights in the presence of spectral mollification. We demonstrate our method in scenes combining fluorescence and transport phenomena that are difficult to render with unidirectional or spectrally discrete methods.

An efficient approach for in-band radar cross section (RCS) reduction of microstrip patch array antenna without employing extra-low RCS artificial materials is proposed and analysed. The element of...

The diffuse reflectance spectra from green coniferous and deciduous leaves of trees and shrubs growing in Krasnodar region are compared with the diffuse reflectance spectra from green synthetic decorative and artificial leaves and various camouflage materials. It is proposed to use vegetation indices of “greenness” for the discrimination of coniferous and deciduous leaves of trees and shrubs from decorative and artificial materials by optical diffuse reflectance spectroscopy.

Recent efforts in engineering metals with high structural efficiency have resulted in developing a new category of artificial materials with heterogeneous microstructures architected across multipl...

Modern medicine would be impractical without the implementation of various artificial materials. In the current generation, the materials implemented for hip and knee joint implants are polymers, metals, ceramics that have been widely overlooked for more than decades. Among them, Ni-Ti, Cu-Al-Ni, Cu-Zn-Al, UHMWPE, PTFE, PEEK these are few alloys and polymers that play a vital role in the Knee and Hip Replacement that comes up with excellent properties and biocompatibility among other materials. In medicine, Shape Memory Materials offer great potential for recollecting a preceding memorized shape. This advanced performance makes Shape Memory Materials worthy and promising materials for various biomedical applications. This paper will provide an extensive review of standards, Manufacturing of materials, advantages of foremost Shape Memory Alloys and, Polymers for Hip and Knee joint replacement. This paper will give the guidelines to future research in impact on hip and knee implants.

For the preparation of modern cement and concrete, supplementary cementitious materials (SCM) have become essential ingredients. The technical, economic and environmental advantages of using SCM have become unquestionable. The main technical reasons for their use are the improvement of the workability of fresh concrete and durability of hardened concrete. Actually, SCM affect almost all concrete properties, while environmental and economic reasons may be more significant than technical reasons. These ingredients can reduce the amount of Portland cement used in cement composites, resulting in economic and environmental benefits. In addition, many of the SCM are industrial by-products, which can otherwise be considered as waste. This paper presents a literature review of the present knowledge on the impact of natural zeolite, waste construction brick and waste container glass on physical, chemical and mechanical properties of Portland cement as the most commonly used cement in the world.

A novel compact Vivaldi Antenna (CVA) for short-pulse ground penetrating radar (GPR) systems is presented. Artificial materials lens (AML) and sidelobe suppressor (SSR) are loaded to improve GPR Antenna's radiation capability in the aperture and the flanks of the CVA. The simulation and experimental results indicate that the proposed CVA has a -10 dB impedance bandwidth of 100% (0.7-2.1 GHz) and a -3 dB gain bandwidth of 70.9% (1.0-2.1 GHz). Within the operating bandwidth of the CVA, AML primarily enhances the CVA's high-frequency gain (1.4-2.1GHz), while the SSR primarily enhances the CVA's low-frequency gain (0.7-1.4 GHz). Moreover, the CVA loaded with two kinds of artificial materials (AMs) has an average gain of 1 dB and 2 dB in the low-frequency and high-frequency parts, respectively. In addition, the transmission response with small ringing in time domain makes the proposed CVA suitable for short-pulse GPR systems. AML and SSR effectively enhance the gain of the CVA with a compact and space-saving loading method, which provides a new idea to enhance the gain of the CVA by artificial material.

In nature, organisms control their deformation and locomotion through multi-functional synergy in response to environmental changes. Nowadays, most synthetic biomaterial systems are capable of realizing single-mode actuation movement under external triggers through biomimetic simulation, while complicated and continuous locomotion in artificial materials with multi-dimensional responsiveness remains to be explored. Here we report an anisotropic melem-formaldehyde polymer that is self-assembled from a one-dimensional (1D) chain into a two-dimensional (2D) film. The stimuli-responsive polymer film shows anisotropic responses in both radial and axial directions on contacting with different solvents (liquid or vapor) in a single material. Complex multi-dimensional motion patterns can be actuated and reversibly controlled by virtue of different interactions within the 1D line and 2D film as well as the gradients along the thickness direction. The developed architecture with tunable and programmable anisotropy is potentially applicable in soft material actuators that can operate in various environments.

Metamaterials are the artificial material having negative properties of permittivity and permeability. Such types of artificial materials exhibit many unnatural properties that do not exist in nature. These unnatural properties can be utilized in many smart devices for beamforming, suppressing reactive fields, SAR and size minimization. The study emphasis on structural modeling of double negative metamaterials having frequency reconfigurable properties. The design is evaluated for negative characteristics of refractive index, permittivity and permeability using novel flower leaf resonator. The proposed unit cell consists of a compact size square shaped FR4 dielectric substrate with dual side printing of metallic flower. The design is exhibiting reconfigurable properties with the variation in the number of leaves and is capable of shifting its transition to the lower end with the increasing number of leaves. The novel structure is compact enough (5 × 5 mm2) to be fit in any metamaterial application. The design is simulated and analyzed using CST microwave studio.