Residual Vibration Suppression of Piezoelectric Inkjet Printing Based on Particle Swarm Optimization Algorithm.

Piezoelectric inkjet printing technology, known for its high precision and cost-effectiveness, has found extensive applications in various fields. However, the issue of residual vibration significantly limits its printing quality and efficiency. This paper presents a method for suppressing residual vibration based on the particle swarm optimization (PSO) algorithm.

Anthropomorphic motion planning for multi-degree-of-freedom arms.

With the development of technology, the humanoid robot is no longer a concept, but a practical partner with the potential to assist people in industry, healthcare and other daily scenarios. The basis for the success of humanoid robots is not only their appearance, but more importantly their anthropomorphic behaviors, which is crucial for the human-robot interaction. Conventionally, robots are designed to follow meticulously calculated and planned trajectories, which typically rely on predefined algorithms and models, resulting in the inadaptability to unknown environments.

High-precision 3D printing of multi-branch vascular scaffold with plasticized PLCL thermoplastic elastomer.

Three-dimensional (3D) printing has emerged as a transformative technology for tissue engineering, enabling the production of structures that closely emulate the intricate architecture and mechanical properties of native biological tissues. However, the fabrication of complex microstructures with high accuracy using biocompatible, degradable thermoplastic elastomers poses significant technical obstacles. This is primarily due to the inherent soft-matter nature of such materials, which complicates real-time control of micro-squeezing, resulting in low fidelity or even failure.

Quantitative Biofabrication Platform for Collagen-Based Peripheral Nerve Grafts with Structural and Chemical Guidance.

Owing to its crucial role in the human body, collagen has immense potential as a material for the biofabrication of tissues and organs. However, highly refined fabrication using collagen remains difficult, primarily because of its notably soft properties. A quantitative biofabrication platform to construct collagen-based peripheral nerve grafts, incorporating bionic structural and chemical guidance cues, is introduced.

A planar per-borylated digermene.

A tetraboryl digermene synthesized by the reaction between a dianionic digermanide nucleophile and a boron halide electrophile is dimeric both in the solid state and in hydrocarbon solution. It features both a planar 'alkene-like' geometry for the GeB core, and an exceptionally short GeGe double bond. These structural features are consistent with the known electronic properties of the boryl group, and with lowest energy () fragmentation into two triplet bis(boryl)germylene fragments.

3D bioprinting microgels to construct implantable vascular tissue.

Engineered implantable functional thick tissues require hierarchical vasculatures within cell-laden hydrogel that can mechanically withstand the shear stress from perfusion and facilitate angiogenesis for nutrient transfer. Yet current extrusion-based 3D printing strategies are unable to recapitulate hierarchical networks, highlighting the need for bioinks with tunable properties. Here, we introduce an approach whereby crosslinkable microgels enhance mechanical stability and induce spontaneous microvascular networks comprised of human umbilical cord vein endothelial cells (HUVECs) in a soft gelatin methacryoyl (GelMA)-based bioink.

Bioprinting of light-crosslinkable neutral-dissolved collagen to build implantable connective tissue with programmable cellular orientation.

Fabricating connective tissue with printing fidelity, structural stability, biocompatibility, and cellular orientation remains a challenge for bioink. Collagen, as inherent fibers to provide strength, should be the ideal material for tissue printing. However, current collagen-bioink exhibits poor printability and mechanical properties.

Vascularized organ bioprinting: From strategy to paradigm.

Over the past two decades, 3D bioprinting has become a popular research topic worldwide, as it is the most promising approach for manufacturing vascularized organs in vitro. However, transitioning from bioprinting of simple tissue models to real biomedical applications is still a challenge due to incomplete interdisciplinary theoretical knowledge and imperfect multi-technology integration. This review examines the goals of vasculature manufacturing and proposes new strategic objectives in three stages.

Dynamic degradation patterns of porous polycaprolactone/β-tricalcium phosphate composites orchestrate macrophage responses and immunoregulatory bone regeneration.

Biodegradable polycaprolactone/β-tricalcium phosphate (PT) composites are desirable candidates for bone tissue engineering applications. A higher β-tricalcium phosphate (TCP) ceramic content improves the mechanical, hydrophilic and osteogenic properties of PT scaffolds . Using a dynamic degradation reactor, we established a steady degradation model to investigate the changes in the physio-chemical and biological properties of PT scaffolds during degradation.

Synthesis of Homo-Metallic Heavier Analogues of Cyclobutene and the Cyclobutadiene Dianion.

The reduction of the boryl-substituted Sn bromide {(HCDippN) B}Sn(IPrMe)Br with 1.5 equivalents of potassium graphite leads to the generation of the cyclic tetratin tetraboryl system K [Sn {B(NDippCH) } ], a homo-metallic heavier analogue of the cyclobutadiene dianion. This system is non-aromatic as determined by Nucleus Independent Chemical Shift Calculations (NICS(0)=-0.

Disproportionation and Ligand Lability in Low Oxidation State Boryl-Tin Chemistry.

Boryltin compounds featuring the metal in the+1 or 0 oxidation states can be synthesized from the carbene-stabilized tin(II) bromide (boryl)Sn(NHC)Br (boryl={B(NDippCH) }; NHC=C{(N PrCMe) }) by the use of strong reducing agents. The formation of the mono-carbene stabilized distannyne and donor-free distannide systems (boryl)SnSn(IPrMe)(boryl) (2) and K [Sn (boryl) ] (3), using Mg(I) and K reducing agents mirrors related germanium chemistry. In contrast to their lighter congeners, however, systems of the type [Sn(boryl)] are unstable with respect to disproportionation.

Numerical Simulation and Experimental Verification of Residual Stress in the Welded Joints of Weldolet-Branch Pipe Dissimilar Steels.

It is well known that welding dissimilar metals can play the advantages and characteristics of those different metals, but it is easy to encounter some problems. In this paper, the thermomechanical behavior of the weldolet-branch dissimilar steel joints in different welding cases is analyzed by establishing a three-dimensional finite element model, and the predicted thermal cycling and residual stresses are verified using experimental tools. The results show that the high temperature area and the heat affected zone on the side of the branch pipe are larger, and there is a large stress gradient at the fusion line on both sides of the weld.

Large full-thickness wounded skin regeneration using 3D-printed elastic scaffold with minimal functional unit of skin.

Traditional tissue engineering skin are composed of living cells and natural or synthetic scaffold. Besize the time delay and the risk of contamination involved with cell culture, the lack of autologous cell source and the persistence of allogeneic cells in heterologous grafts have limited its application. This study shows a novel tissue engineering functional skin by carrying minimal functional unit of skin (MFUS) in 3D-printed polylactide-co-caprolactone (PLCL) scaffold and collagen gel (PLCL + Col + MFUS).

Fully Reduced HMGB1-Containing Peptide-Based Polyurethane Scaffold with Minimal Functional Unit of Skin (MFUS) Enhances Large and Deep Wounded Skin Healing.

A novel peptide-based polymer is developed by lysine-diisocyanate (LDI), glycerol (Gly), and fully reduced HMGB1 (frHMGB1). This frHMGB1-LDI-Gly polymer either forms sponge-like foam (scaffold) or a hydrogel or a film under different reaction conditions. It degrades into nontoxic lysine, glycerol, and frHMGB1.

Influence of Interlayer Temperature and Welding Sequence on the Temperature Distribution and Welding Residual Stress of the Saddle-Shaped Joint of Weldolet-Header Butt Welding.

In this paper, based on Simufact Welding finite element analysis software, a numerical simulation of the temperature and residual stress distribution of the weldolet-header multi-layer multi-pass welding process is carried out, and the simulation results are verified through experiments. The experimental results are in good agreement with the numerical simulation results, which proves the validity of the numerical simulation results. Through the results of the numerical simulation, the influence of the welding sequence and interlayer temperature on the temperature and residual stress distribution at different locations of the saddle-shaped weld was studied.

Anthropomorphic Reaching Movement Generating Method for Human-Like Upper Limb Robot.

How to generate anthropomorphic reaching movement remains a challenging problem in service robots and human motor function repair/reconstruction equipment. However, there is no universally accepted computational model in the literature for reproducing the motion of the human upper limb. In response to the problem, this article presents a computational framework for generating reaching movement endowed with human motion characteristics that imitated the mechanism in the control and realization of human upper limb motions.

3D Liver Tissue Model with Branched Vascular Networks by Multimaterial Bioprinting.

Complicated vessels pervade almost all body tissues and influence the pathophysiology of the human body significantly. However, current fabrication strategies have limited success at multiscale vascular biofabrication. This study reports a methodology to fabricate soft vascularized tissue at centimeter scale using multimaterial bioprinting by a customized multistage-temperature-control printer.

Colorimetric Metal-Free Detection of Carbon Monoxide: Reversible CO Uptake by a BNB Frustrated Lewis Pair.

We report two BNB-type frustrated Lewis pairs which feature an acceptor-donor-acceptor functionalized cavity, and which differ in the nature of the B-bound fluoroaryl group (C F vs. C H (CF ) -3,5, Ar ). These receptor systems are capable of capturing gaseous CO, and in the case of the -BAr system this can be shown to occur in reversible fashion at/above room temperature.

Collagen-Based Thiol-Norbornene Photoclick Bio-Ink with Excellent Bioactivity and Printability.

As the essential foundation of bioprinting technology, cell-laden bio-ink is confronted with the inevitable contradiction between printability and bioactivity. For example, type I collagen has been widely applied for its excellent biocompatibility; however, its relatively low self-assembly speed restricts the performance in high-precision bioprinting of cell-laden structures. In this study, we synthesize norbornene-functionalized neutral soluble collagen (NorCol) by the reaction of acid-soluble collagen (Col) and carbic anhydride in the aqueous phase.

Valve-based consecutive bioprinting method for multimaterial tissue-like constructs with controllable interfaces.

Bioprinting is a promising technology focusing on tissue manufacturing, whose vital problem is the precise assembly of multiple materials. As the primary solution, the extrusion-based multi-printhead bioprinting (MPB) method requires printhead switching during the printing process, which induces inefficient motion time and material interface defects. We present a valve-based consecutive bioprinting (VCB) method to resolve these problems, containing a precise integrated switching printhead and a well-matched voxelated digital model.

A Xanthene-Based Mono-Anionic PON Ligand: Exploiting a Bulky, Electronically Unsymmetrical Donor in Main Group Chemistry.

The synthesis of a novel mono-anionic phosphino-amide ligand based on a xanthene backbone is reported, togetherr with the corresponding Ga complex, (PON)Ga (PON = 4-(di(2,4,6-trimethylphenyl)phosphino)-5-(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). The solid-state structure of (PON)Ga (obtained from X-ray crystallography) reveals very weak O⋅⋅⋅Ga and P⋅⋅⋅Ga interactions, consistent with a R NGa fragment which closely resembles those found in one-coordinate amidogallium systems. Strong N-to-Ga π donation from the amido substituent is reflected in a very short N-Ga distance (1.

Fabrication of 3D Scaffolds Displaying Biochemical Gradients along Longitudinally Oriented Microchannels for Neural Tissue Engineering.

Biochemical and physical guidance cues are both pivotal for axonal guidance and nerve regeneration. However, fabrication of a platform that can integrate biochemical gradients and topographical guidance cues remains challenging, especially in a three-dimensional (3D) scaffold that closely mimics axonal outgrowth conditions and ready to be used for nerve repair. In this study, a new method was introduced to construct 3D scaffolds displaying continuous biochemical gradients along longitudinally oriented microchannels by combining the modified 3D printing and directional freezing techniques.

Li(NH)BH: a new ionic liquid octahydrotriborate.

We report a strategy of using small cations to construct ionic liquid octahydrotriborate. The novel liquid Li(NH3)B3H8, prepared by a facile reaction of NH4B3H8 with LiH, froze below -33.4 °C and crystallized into a monoclinic unit cell with lattice parameters of a = 8.

Facile preparation and dehydrogenation of unsolvated KBH.

An efficient synthesis of unsolvated KBH was achieved by the reaction of a liquid K-Na alloy with BH·THF at room temperature. KBH was found to release hydrogen and minor boranes by subsequent cleavage of its B-H and B-H-B bonds during pyrolysis, and yield KBH as a major product.