Acoustic Signal-Based Defect Identification for Directed Energy Deposition-Arc Using Wavelet Time-Frequency Diagrams.

Several advantages of directed energy deposition-arc (DED-arc) have garnered considerable research attention including high deposition rates and low costs. However, defects such as discontinuity and pores may occur during the manufacturing process. Defect identification is the key to monitoring and quality assessments of the additive manufacturing process.

Peptide-dendrimer-reinforced bioinks for 3D bioprinting of heterogeneous and biomimetic in vitro models.

Despite 3D bioprinting having emerged as an advanced method for fabricating complex in vitro models, developing suitable bioinks that fulfill the opposing requirements for the biofabrication window still remains challenging. Although naturally derived hydrogels can better mimic the extracellular matrix (ECM) of numerous tissues, their weak mechanical properties usually result in architecturally simple shapes and patchy functions of in vitro models. Here, this limitation is addressed by a peptide-dendrimer-reinforced bioink (HC-PDN) which contained the peptide-dendrimer branched PEG with end-grafted norbornene (PDN) and the cysteamine-modified HA (HC).

Electroactive shape memory polyurethane composites reinforced with octadecyl isocyanate-functionalized multi-walled carbon nanotubes.

Shape memory polymers (SMPs) have a wide range of potential applications in many fields. In particular, electrically driven SMPs have attracted increasing attention due to their unique electrical deformation behaviors. Carbon nanotubes (CNTs) are often used as SMP conductive fillers because of their excellent electrical conductivities.

Hydrogels for 3D embedded bioprinting: a focused review on bioinks and support baths.

Three-dimensional (3D) bioprinting has played an increasingly crucial role in the manufacturing of organized complex tissues and organs, which has shown tremendous potential in the field of tissue engineering. Extrusion-based bioprinting takes advantage of its competitive pricing and flexibility to print various biomaterials, and it has now developed into one of the most used printing techniques. However, extruding soft hydrogels, also known as bioinks, often leads to poor fidelity when printed in air.

A review of flexible force sensors for human health monitoring.

Background: In recent years, health monitoring systems (HMS) have aroused great interest due to their broad prospects in preventive medicine. As an important component of HMS, flexible force sensors (FFS) with high flexibility and stretch-ability can monitor vital health parameters and detect physical movements.

Aim Of Review: In this review, the novel materials, the advanced additive manufacturing technologies, the selective sensing mechanisms and typical applications in both wearable and implantable HMS are discussed.

Channel innovations for inertial microfluidics.

Inertial microfluidics has gained significant attention since first being proposed in 2007 owing to the advantages of simplicity, high throughput, precise manipulation, and freedom from an external field. Superior performance in particle focusing, filtering, concentrating, and separating has been demonstrated. As a passive technology, inertial microfluidics technology relies on the unconventional use of fluid inertia in an intermediate Reynolds number range to induce inertial migration and secondary flow, which depend directly on the channel structure, leading to particle migration to the lateral equilibrium position or trapping in a specific cavity.

Fluid-Structure Interaction Analysis of Perfusion Process of Vascularized Channels within Hydrogel Matrix Based on Three-Dimensional Printing.

The rise of three-dimensional bioprinting technology provides a new way to fabricate in tissue engineering in vitro, but how to provide sufficient nutrition for the internal region of the engineered printed tissue has become the main obstacle. In vitro perfusion culture can not only provide nutrients for the growth of internal cells but also take away the metabolic wastes in time, which is an effective method to solve the problem of tissue engineering culture in vitro. Aiming at user-defined tissue engineering with internal vascularized channels obtained by three-dimensional printing experiment in the early stage, a simulation model was established and the in vitro fluid-structure interaction finite element analysis of tissue engineering perfusion process was carried out.

Fabrication of Microfluidic Chips Based on an EHD-Assisted Direct Printing Method.

Microfluidic chips have been widely used in many areas such as biology, environmental monitoring, and micromixing. With the increasing popularity and complexity of microfluidic systems, rapid and convenient approaches for fabricating microfluidic chips are necessary. In this study, a method based on EHD (electrohydrodynamic)-assisted direct printing is proposed.

The Research on Multi-material 3D Vascularized Network Integrated Printing Technology.

Three-dimensional bioprinting has emerged as one of the manufacturing approaches that could potentially fabricate vascularized channels, which is helpful to culture tissues in vitro. In this paper, we report a novel approach to fabricate 3D perfusable channels by using the combination of extrusion and inkjet techniques in an integrated manufacture process. To achieve this, firstly we investigate the theoretical model to analyze influencing factors of structural dimensions of the printed parts like the printing speed, pressure, dispensing time, and voltage.

Synthesis of Samarium-Based Metal Organic Compound Nanoparticles with Polychromatic-Photoluminescence for Bio-Tissue Fluorescence Imaging.

The development of nanomaterials with special optical window is critical for clinical applications and the optoelectronic industry. In this work, eight kinds of samarium-based metal organic compound nanoparticles (Sm-Fe, Sm-Ga, Sm-Mn, Sm-Na, Sm-Nb, Sm-W, Sm-Cu, and Sm-Al) were synthesized through a solution method. They show polychromatic-photoluminescence spectra extended from the UV to near-infrared (NIR) region when excited by 280 nm, 380 nm, 480 nm, 580 nm, and 785 nm light.

Fabrication of Different Microchannels by Adjusting the Extrusion Parameters for Sacrificial Molds.

Using the 3D printed mold-removal method to fabricate microchannel has become a promising alternative to the conventional soft lithography technique, due to the convenience in printing channel mold and the compatibility with PDMS material. Although having great potential, the use of single filament extruded by fused deposition modeling (FDM) as the sacrificial channel mold has not been elaborately studied. In this paper, we demonstrate the fabrication of microchannels with different structure and size by controllably extruding the sacrificial channel molds.

Design and biomechanical characteristics of porous meniscal implant structures using triply periodic minimal surfaces.

Background: Artificial meniscal implants can be used to replace a severely injured meniscus after meniscectomy and restore the normal functionality of a knee joint. The aim of this paper was to design porous meniscal implants and assess their biomechanical properties.

Methods: Finite element simulations were conducted on eight different cases including intact healthy knees, knee joints with solid meniscal implants, and knee joints with meniscal implants with two types of triply periodic minimal surfaces.

Mechanical characterization of 3D printed multi-morphology porous Ti6Al4V scaffolds based on triply periodic minimal surface architectures.

Heterogeneous biomaterials that simultaneously mimic the topological and mechanical properties of nature bone tissues are of great interest in recent years. In this study, multi-morphology porous scaffolds based on the triply periodic minimal surfaces (TPMS) were designed and 3D printed with spatially changing pore patterns. Experiments and numerical analyses were carried out to assess the mechanical properties of the multi-morphology graded porous scaffold.

Recent advances in microfluidic cell sorting techniques based on both physical and biochemical principles.

Microfluidic technologies for isolating cells of interest from a heterogeneous sample have attracted great attentions, due to the advantages of less sample consumption, simple operating procedure, and high separation accuracy. According to the working principles, the microfluidic cell sorting techniques can be categorized into biochemical (labeled) and physical (label-free) methods. However, the inherent drawbacks of each type of method may somehow influence the popularization of these cell sorting techniques.

A TPMS-based method for modeling porous scaffolds for bionic bone tissue engineering.

In the field of bone defect repair, gradient porous scaffolds have received increased attention because they provide a better environment for promoting tissue regeneration. In this study, we propose an effective method to generate bionic porous scaffolds based on the TPMS (triply periodic minimal surface) and SF (sigmoid function) methods. First, cortical bone morphological features (e.

Application of virtual reality technology in clinical medicine.

The present review discusses the application of virtual reality (VR) technology in clinical medicine, especially in surgical training, pain management and therapeutic treatment of mental illness. We introduce the common types of VR simulators and their operational principles in aforementioned fields. The clinical effects are also discussed.

In situ repair of bone and cartilage defects using 3D scanning and 3D printing.

Three-dimensional (3D) printing is a rapidly emerging technology that promises to transform tissue engineering into a commercially successful biomedical industry. However, the use of robotic bioprinters alone is not sufficient for disease treatment. This study aimed to report the combined application of 3D scanning and 3D printing for treating bone and cartilage defects.

Wavelet Entropy and Directed Acyclic Graph Support Vector Machine for Detection of Patients with Unilateral Hearing Loss in MRI Scanning.

We develop computer-aided diagnosis system for unilateral hearing loss detection in structural magnetic resonance imaging.Wavelet entropy is introduced to extract image global features from brain images. Directed acyclic graph is employed to endow support vector machine an ability to handle multi-class problems.

YAP and 14-3-3γ are involved in HS-OA-induced growth inhibition of hepatocellular carcinoma cells: A novel mechanism for hydrogen sulfide releasing oleanolic acid.

Hydrogen sulfide-releasing oleanolic acid (HS-OA) is an emerging novel class of compounds and consists of an oleanolic acid (OA) and a H2S-releasing moiety. Although it exhibits improved anti-inflammatory activity, its potency in human cancers has not been understood yet. In this study, we examined the effects of HS-OA on the growth of liver cancer cell lines and the underlying mechanisms.

Preliminary research on abnormal brain detection by wavelet-energy and quantum- behaved PSO.

It is important to detect abnormal brains accurately and early. The wavelet-energy (WE) was a successful feature descriptor that achieved excellent performance in various applications; hence, we proposed a WE based new approach for automated abnormal detection, and reported its preliminary results in this study. The kernel support vector machine (KSVM) was used as the classifier, and quantum-behaved particle swarm optimization (QPSO) was introduced to optimize the weights of the SVM.

A Novel Compressed Sensing Method for Magnetic Resonance Imaging: Exponential Wavelet Iterative Shrinkage-Thresholding Algorithm with Random Shift.

Aim. It can help improve the hospital throughput to accelerate magnetic resonance imaging (MRI) scanning. Patients will benefit from less waiting time.

Digital Microdroplet Ejection Technology-Based Heterogeneous Objects Prototyping.

An integrate fabrication framework is presented to build heterogeneous objects (HEO) using digital microdroplets injecting technology and rapid prototyping. The heterogeneous materials part design and manufacturing method in structure and material was used to change the traditional process. The net node method was used for digital modeling that can configure multimaterials in time.

Image processing methods to elucidate spatial characteristics of retinal microglia after optic nerve transection.

Microglia are the mononuclear phagocytes with various functions in the central nervous system, and the morphologies of microglia imply the different stages and functions. In optical nerve transection model of the retina, the retrograde degeneration of retinal ganglion cells induces microglial activations to a unique morphology termed rod microglia. A few studies described the rod microglia in the cortex and retina; however, the spatial characteristic of rod microglia is not fully understood.

Three-Dimensional Eigenbrain for the Detection of Subjects and Brain Regions Related with Alzheimer's Disease.

Background: Considering that Alzheimer's disease (AD) is untreatable, early diagnosis of AD from the healthy elderly controls (HC) is pivotal. However, computer-aided diagnosis (CAD) systems were not widely used due to its poor performance.

Objective: Inspired from the eigenface approach for face recognition problems, we proposed an eigenbrain to detect AD brains.