Microalgae-Based Biohybrid Microrobot for Accelerated Diabetic Wound Healing

A variety of wound healing platforms have been proposed to alleviate the hypoxic condition and/or to modulate the immune responses for the treatment of chronic wounds in diabetes. However, these platforms with the passive diffusion of therapeutic agents through the blood clot result in the relatively low delivery efficiency into the deep wound site. Here, a microalgae-based biohybrid microrobot for accelerated diabetic wound healing is developed. The biohybrid microrobot autonomously moves at velocity of 33.3 µm s⁻¹ and generates oxygen for the alleviation of hypoxic condition. In addition, the microrobot efficiently bound with inflammatory chemokines of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) for modulating the immune responses. The enhanced penetration of microrobot is corroborated by measuring fibrin clots in biomimetic wound using microfluidic devices and the enhanced retention of microrobot is confirmed in the real wounded mouse skin tissue. After deposition on the chronic wound in diabetic mice without wound dressing, the wounds treated with microrobots are completely healed after 9 days with the significant decrease of inflammatory cytokines below 31% of the control level and the upregulated angiogenesis above 20 times of CD31⁺ cells. These results confirm the feasibility of microrobots as a next-generation platform for diabetic wound healing.     

Regulation of Polymer Configurations Enables Green Solvent-Processed Large-Area Binary All-Polymer Solar Cells With Breakthrough Performance and High Efficiency Stretchability Factor

With the great potential of the all-polymer solar cells for large-area wearable devices, both large-area device efficiency and mechanical flexibility are very critical but attract limited attention. In this work, from the perspective of the polymer configurations, two types of terpolymer acceptors PYTX-A and PYTX-B (X = Cl or H) are developed. The configuration difference caused by the replacement of non-conjugated units results in distinct photovoltaic performance and mechanical flexibility. Benefiting from a good match between the intrinsically slow film-forming of the active materials and the technically slow film-forming of the blade-coating process, the toluene-processed large-area (1.21 cm²) binary device achieves a record efficiency of 14.70%. More importantly, a new parameter of efficiency stretchability factor (ESF) is proposed for the first time to comprehensively evaluate the overall device performance. PM6:PYTCl-A and PM6:PYTCl-B yield significantly higher ESF than PM6:PY-IT. Further blending with non-conjugated polymer donor PM6-A, the best ESF of 3.12% is achieved for PM6-A:PYTCl-A, which is among the highest comprehensive performances.     

Absorption effect in the calculation of a second-order nonlinear coefficient from the data of a maker fringe experiment

The effect of light absorption by sample in the analysis of Makerfringe data for estimating a second-order nonlinear coefficient hasbeen studied experimentally. Two theories, one by Jerphagnon andKurtz that neglects the absorption effect and one by Herman and Haydenthat takes into account the absorption effect, were compared with theexperimental results. It was found that Jerphagnon and Kurtz'sformula was unable to predict correctly not only the magnitude but alsothe incident angle dependence or the sample thickness dependence of thesecond harmonic signal generated by the sample with strong absorption, whereas the theory by Herman and Hayden was able to make thosepredictions fairly well. It was also found that the error in theestimated nonlinear coefficient when one uses Jerphagnon and Kurtz'sformula could be as large as 2-4 times the true value, depending onsample thickness.     

Magnetic compass fault detection method for GPS/INS/magnetic compass integrated navigation systems

This paper proposes a magnetic compass fault detection method for GPS/INS/Magnetic compass integrated navigation systems. The fault is assumed to be caused by the hard iron and soft iron effect and modeled as an abrupt change in the magnetic compass output. In order to detect the fault, a test statistic related with only azimuth error measurement is determined. When a fault is detected, the GPS/INS/Magnetic compass integrated navigation system is changed into a GPS/INS integrated navigation system mode. In order to show the validity of the proposed method, computer simulation and van testing are carried out. The simulation and van test results show that the proposed navigation system gives more accurate outputs than the GPS/INS/Magnetic compass without the proposed method.     

Tissue dynamics spectroscopy for three-dimensional tissue-based drug screening

Tissue dynamics spectroscopy combines dynamic light scattering with short-coherence digital holography to capture intracellular motion inside multicellular tumor spheroid tissue models. The cellular mechanical activity becomes an endogenous imaging contrast agent for motility contrast imaging. Fluctuation spectroscopy is performed on dynamic speckle from the proliferating shell and hypoxic core to generate drug-response spectrograms that are frequency versus time representations of the changes in spectral content induced by an applied compound or an environmental perturbation. A combination of 28 reference compounds and conditions applied to rat osteogenic UMR-106 spheroids generated spectrograms that were crosscorrelated in a similarity matrix used for unsupervised hierarchical clustering of similar compound responses. This work establishes the feasibility of tissue dynamics spectroscopy for three-dimensional tissue-based phenotypic profiling of drug response as a fully endogenous probe of the response of tissue to reference compounds.     

Study of polymer‐network structure on polymer‐stabilized blue phase

Abstract— To understand the mechanism of the disclination defect of the liquid‐crystal (LC) phase, this study was conducted to directly analyze the polymer‐network (PN) structure of polymer‐stabilized blue phase (PSBP), which is minutely formed on all LC layers. The PN was examined after first removing the glass decap and then the LC. Important to note is that the removal of the glass decap did not affect or damage the PN structure. The PN was determined to be a stable structure without any change to the thickness of the layer. When removing the LC, both hexane and acetone solutions were used. Moreover, there was no structural deformation to the PN when using the hexane solution. The results of the study show that the actual size of the polymer chain is in fact 50–60 nm, five times larger than previous theories which estimated the size to be only 10 nm. In addition, this study confirmed that the pores between the PN are 100–200 nm. The PN structure was shown to be susceptible to change based on different heating temperatures. In summation, now that defect lines of a LC display (LCD) could be directly measured, further progress and development in the theoretical interpretations of the Kerr effect on PSBP can be realized.     

Memory effects of all‐solution‐processed oxide thin‐film transistors using ZnO nanoparticles

Abstract— Non‐volatile memory effects of an all‐solution‐processed oxide thin‐film transistor (TFT) with ZnO nanoparticles (NPs) as the charge‐trapping layer are reported. The device was fabricated by using a soluble MgInZnO active channel on a ZrHfO^x gate dielectric. ZnO NPs were used as the charge‐trapping site at the gate‐insulator—channel interface, and Al was used for source and drain electrodes. Transfer characteristics of the device showed a large clockwise hysteresis, which can be used to demonstrate its memory function due to electron trapping in the ZnO NP charge‐trapping layer. This memory effect has the potential to be utilized as a memory application on displays and disposable electronics.     

Binding conformation prediction between human acetylcholinesterase and cytochrome c using molecular modeling methods

The acetylcholinesterase (AChE) is important to terminate acetylcholine-mediated neurotransmission at cholinergic synapses. The pivotal role of AChE in apoptosome formation through the interactions with cytochrome c (Cyt c) was demonstrated in recent study. In order to investigate the proper binding conformation between the human AChE (hAChE) and human Cyt c (hCyt c), macro-molecular docking simulation was performed using DOT 2.0 program. The hCyt c was bound to peripheral anionic site (PAS) on hAChE and binding mode of the docked conformation was very similar to the reported crystal structure of the AChE and fasciculin-II (Fas-II) complex. Two 10ns molecular dynamics (MD) simulations were carried out to refine the binding mode of docked structure and to observe the differences of the binding conformations between the absent (Apo) and presence (Holo) of heme group. The key hydrogen bonding residues between hAChE and hCyt c proteins were found in Apo and Holo systems, as well as each Tyr341 and Trp286 residue of hAChE was participated in cation-pi (π) interactions with Lys79 of hCyt c in Apo and Holo systems, respectively. From the present study, although the final structures of the Apo and Holo systems have similar binding pattern, several differences were investigated in flexibilities, interface interactions, and interface accessible surface areas. Based on these results, we were able to predict the reasonable binding conformation which is indispensable for apoptosome formation.     

Spin-valve planar Hall sensor for single bead detection

The planar Hall effect (PHE) sensor with a junction size of 3 μm × 3 μm for a single micro-bead detection has been fabricated successfully using a typical spin-valve thin film Ta(5)/NiFe(16)/Cu(1.2)/NiFe(2)/IrMn(15)/Ta(5) nm. The PHE sensor exhibits a sensitivity of about 7.2 μV Oe^?1 in the magnetic field range of ±7 Oe approximately. We have performed an experiment to illustrated the possibility of single micro-bead detection by using a PHE sensor. A single micro-bead of 2.8 μm diameter size is secluded from 0.1% dilute solution of the Dynabeads^® M-280 dropped on the sensor surface and is located on the sensor junction by using a micro magnetic needle. The comparison of the PHE voltage profiles in the field range from 0 to 20 Oe in the absence and presence of a single micro-bead identifies a single Dynabeads^® M-280, the maximal signal change as large as ΔV ～ 1.1 μV can be obtained at the field ～6.6 Oe. The results are well described in terms of the reversal of a basic single domain structure.