Yih-Shou Hsieh 1, 2 and Shun-Fa Yang 1,3 and Gautam Sethi 4 and Dan-Ning Hu 5 1, Department of Medical Research, Chung Shan Medical University Hospital, Taichung 402, Taiwan 2, Institute of ...Biochemistry and Biotechnology, Chung Shan Medical University, Taichung 402, Taiwan 3, Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan 4, Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 119077, Singapore 5, Tissue Culture Center, New York Eye and Ear Infirmary, New York Medical College, New York, NY 10009, USA Received 18 December 2014; Accepted 18 December 2014; 26 March 2015 This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cardiovascular disease is currently a leading killer to human, while drug‐induced cardiotoxicity remains the main cause of the withdrawal and attrition of drugs. Taking clinical correlation and ...throughput into account, cardiomyocyte is perfect as in vitro cardiac model for heart disease modeling, drug discovery, and cardiotoxicity assessment by accurately measuring the physiological multiparameters of cardiomyocytes. Remarkably, cardiomyocytes present both electrophysiological and biomechanical characteristics due to the unique excitation–contraction coupling, which plays a significant role in studying the cardiomyocytes. This review mainly focuses on the recent advances of biosensing technologies for the 2D and 3D cardiac models with three special properties: electrophysiology, mechanical motion, and contractile force. These high‐performance multidimensional cardiac models are popular and effective to rebuild and mimic the heart in vitro. To help understand the high‐quality and accurate physiologies, related detection techniques are highly demanded, from microtechnology to nanotechnology, from extracellular to intracellular recording, from multiple cells to single cell, and from planar to 3D models. Furthermore, the characteristics, advantages, limitations, and applications of these cardiac biosensing technologies, as well as the future development prospects should contribute to the systematization and expansion of knowledge.
This review focuses on the recent advances of biosensing technologies for the 2D and 3D cardiac models with three special properties: electrophysiology, mechanical motion, and contractile force. Moreover, the characteristics, advantages, limitations, and applications of these cardiac biosensing technologies, as well as the future development prospects are also introduced and discussed.
Thermo-stamping is critical for the structural application of two-dimensional (2D) woven fabric reinforced thermoplastics (WFRTPs). Reliable simulation models for thermo-stamping of 2D WFRTPs can ...effectively reduce the time and tooling cost caused by trial-and-error development, and thus are crucial for mature manufacturing. This article presents a survey of the literature on the characterization and simulation for thermo-stamping of WFRTPs. First, the investigations of the main deformation mechanisms of thermo-stamping and the corresponding experimental characterization methods are summarized. Then, we highlight the development of simulation models for the stamping and cooling steps, as well as the progress in the development of the continuous virtual process chain (CAE chain) for the simulations of the entire forming process and the structural performance prediction of molded parts. As the study on the stamping process becomes mature, a closed simulation optimization chain for WFRTP's thermo-stamping process has gradually been developed to reduce the overall development costs of high-performance WFRTPs.
The 2.5D woven composite material has good resistance to delamination and impact load. However, its fatigue behavior is lack of investigation. In this work, first-order bending vibration fatigue ...tests were conducted on cantilever beam specimens made of 2.5D woven composites under different nominal stress levels. Test results showed that rapid damage evolution and accumulation occurred in the woven composites under a high stress level. However, under a low stress level, crack growth showed arrest behavior. The square root of residual stiffness showed a linear relation with resonance frequency, so the normalized full-time domain curves can be used to characterize the residual stiffness. On that basis, a residual stiffness model for the studied vibration fatigue specimens under other stress levels was proposed. Besides, a formula of ɛ-N curve was established for guiding the design and analysis of the 2.5D woven composite. To further reveal the failure mechanism, a multi-scale model of the woven composite was proposed. Numerical results showed that the high interlaminar shear stress between the yarn and the matrix near the compressed surface of the specimen caused material damage. This was consistent with the observed fracture topography, which verified the applicability of the multi-scale model.
Cortical areas including the anterior cingulate cortex (ACC) play critical roles in different types of chronic pain. Most of previous studies focus on the sensory inputs from somatic areas, and less ...information about plastic changes in the cortex for visceral pain. In this study, chronic visceral pain animal model was established by injection with zymosan into the colon of adult male C57/BL6 mice. Whole cell patch‐clamp recording, behavioral tests, western blot, and Cannulation and ACC microinjection were employed to explore the role of adenylyl cyclase 1 (AC1) in the ACC of C57/BL6 and AC1 knock out mice. Integrative approaches were used to investigate possible changes of neuronal AC1 in the ACC after the injury. We found that AC1, a key enzyme for pain‐related cortical plasticity, was significantly increased in the ACC in an animal model of irritable bowel syndrome. Inhibiting AC1 activity by a selective AC1 inhibitor NB001 significantly reduced the up‐regulation of AC1 protein in the ACC. Furthermore, we found that AC1 is required for NMDA GluN2B receptor up‐regulation and increases of NMDA receptor‐mediated currents. These results suggest that AC1 may form a positive regulation in the cortex during chronic visceral pain. Our findings demonstrate that the up‐regulation of AC1 protein in the cortex may underlie the pathology of chronic visceral pain; and inhibiting AC1 activity may be beneficial for the treatment of visceral pain.
Anterior cingulate cortex (ACC) plays critical roles in different types of chronic pain. Calcium‐stimulated, neuronal selective adenylyl cyclase subtype 1 (AC1) is critical for injury‐triggered cortical plasticity and chronic pain. We demonstrate that AC1 protein was up‐regulated in the ACC for a long‐period of time in a mouse model of chronic visceral pain. AC1 activity is required for the up‐regulation of AC1 protein, suggesting that AC1 may form a positive feedback in the cortex during chronic visceral pain. This is the first time to demonstrate that AC1 protein can undergo long‐term increases in central neurons after peripheral injuries.
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•A multifunctional superhydrophobic SR/MWCNTs/LIG/SR composite strain sensor is prepared using an entirely laser direct writing method.•It presented outstanding waterproof (water ...contact angle of 155°), anti-corrosion ability (from pH = 1 to pH = 14), and photothermal anti-icing/deicing properties.•It exhibited a high sensitivity of 667, large working range (up to 230%), and remarkable long-term stability (>2500 cycles).•The sensor has potential applications in full-range human body motions monitoring under complex harsh environments.
Superhydrophobic composite strain sensors have attracted extensive attention due to their excellent waterproof, anti-icing, flexible and conductive properties, but there are still challenges to prepare it with broad sensing range, superior sensitivity, stable superhydrophobicity, and excellent long-term stability. In this study, we developed a multifunctional superhydrophobic silicone rubber (SR)/multi-walled carbon nanotubes (MWCNTs)/laser-induced graphene (LIG)/SR composite strain sensor using laser direct writing. A highly stable MWCNTs/LIG crosslinked conductive network layer, high-performance superhydrophobic layer, and stretchable SR layer were integrated to fabricate the sensor by tuning the laser parameters. The SR/MWCNTs/LIG/SR composite strain sensor possessed a high gauge factor of 667, large strain detection range of 0–230%, and a stable sensing response over 2500 cycles due to the MWCNTs/LIG crosslinked conductive network. Moreover, the SR/MWCNTs/LIG/SR composite strain sensor could effectively prevent icing owing to its anti-icing (36 min@-5 °C) and photothermal deicing (88 s@1 W/cm2@NIL) properties and hinder acid and alkaline (pH = 1–14) corrosion attributed to the laser-induced superhydrophobicity, thereby expanding its applications to acid, alkaline, and low-temperature environments. Consequently, the multifunctional superhydrophobic SR/MWCNTs/LIG/SR composite strain sensor is demonstrated to be suitable for human body motion detection in complex and severe environments.
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•The penta-boron nitride nanosheet exhibits ductile behavior under tension instead of brittle behavior in the hexa-boron nitride nanosheet.•Structure transition in the penta-boron ...nitride nanosheet yields progressive failure under tension up to the strain 0.9.•The penta-boron nitride nanosheet extends the collapse strain 0.274 in the hexa-boron nitride nanosheet to 0.9.•The penta-boron nitride nanosheet sustains the load-carrying capacity after bond breaking and crack development.
Boron nitride nanosheet (BNNS) is an attractive nanomaterial to improve polymeric materials in hydrogels due to their high mechanical properties, robust interfacial properties with polymer, and non-toxicity. However, the mismatching deformation capacity between BNNS and hydrogels results in damage to the BNNS-hydrogels interface and deteriorates the tensile properties of BNNS reinforced hydrogels. By adopting nanotechnology, the brittle nature of BNNSs can be modified. A novel penta-BNNS exhibits pentagonal rings, presenting ductile behavior under tensile deformation. The tensile test is performed by molecular dynamics simulations. The simulation results show that the ultimate failure strain of the penta-BNNS is significantly increased, which is attributed to the structure transition of the pentagonal rings in the penta-BNNS under tensile deformation. Due to the structure transition, the deformation capacity of the penta-BNNS is significantly improved with respect to the hexa-BNNS. This study links the structure to ductile behavior, which helps to devise advanced two-dimensional nanomaterials for improving hydrogels.
The one-pot reductive 1,3-dipolar cycloaddition of secondary aromatic N-(trimethylsilylmethyl)amides with reactive dipolarophiles is reported. The method relies on the in situ generation of ...nonstabilized NH azomethine ylide dipoles via amide activation with triflic anhydride, partial reduction with 1,1,3,3-tetramethyldisiloxane (TMDS), and desilylation with cesium fluoride (CsF). Running under mild conditions, the reaction tolerated several sensitive functional groups and provided cycloadducts in 71–93% yields. The use of less reactive dipolarophile methyl acrylate led to the cycloadduct in only 40% yield. A (Z) geometric intermediate of NH-azomethine 1,3-dipole was postulated to account for the observed higher yields and higher cis diastereoselectivity for the substrates bearing an electron-withdrawing group. This model features an unconventional cyclic transition state via carbanion–aryl ring interaction. Because the starting secondary amides can be prepared from common primary amides, the current method also constitutes a two-step transformation of primary amides.
We study the internal stabilization and the boundary stabilization of the critical semilinear Klein–Gordon equation in compact space. The observability inequalities are proved by the Morawetz ...estimates on Riemannian manifold, and then the compactness–uniqueness arguments are used to prove the main stabilization results.
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