Enhanced axon outgrowth of spinal motor neurons in co-culturing with dorsal root ganglions antagonizes the growth inhibitory environment.

Introduction: Forming a bridge made of functional axons to span the lesion is essential to reconstruct the motor circuitry following spinal cord injury (SCI). Dorsal root ganglion (DRG) axons are robust in axon growth and have been proved to facilitate the growth of cortical neurons in a process of axon-facilitated axon regeneration. However, whether DRG transplantation affects the axon outgrowth of spinal motor neurons (SMNs) that play crucial roles in motor circuitry remains unclear. Methods: We investigated the axonal growth patterns of co-cultured DRGs and SMN aggregates (SMNAs) taking advantage of a well-designed 3D-printed in vitro system. Chondroitin sulphate proteoglycans (CSPG) induced inhibitory matrix was introduced to imitate the inhibitory environment following SCI. Axonal lengths of DRG, SMNA or DRG & SMNA cultured on the permissive or CSPG induced inhibitory matrix were measured and compared. Results: Our results indicated that under the guidance of full axonal connection generated from two opposing populations of DRGs, SMNA axons were growth-enhanced and elongated along the DRG axon bridge to distances that they could not otherwise reach. Quantitatively, the co-culture increased the SMNA axonal length by 32.1 %. Moreover, the CSPG matrix reduced the axonal length of DRGs and SMNAs by 46.2 % and 17.7 %, respectively. This inhibitory effect was antagonized by the co-culture of DRGs and SMNAs. Especially for SMNAs, they extended the axons across the CSPG-coating matrix, reached the lengths close to those of SMNAs cultured on the permissive matrix alone. Conclusions: This study deepens our understanding of axon-facilitated reconstruction of the motor circuitry. Moreover, the results support SCI treatment utilizing the enhanced outgrowth of axons to restore functional connectivity in SCI patients.

Photosystem II of Ligustrum lucidum in response to different levels of manganese exposure.

The toxic effect of excessive manganese (Mn) on photosystem II (PSII) of woody species remains largely unexplored. In this study, five Mn concentrations (0, 12, 24, 36, and 48 mM) were used, and the toxicity of Mn on PSII behavior in leaves of Ligustrum lucidum was investigated using in vivo chlorophyll fluorescence transients. Results showed that excessive Mn levels induced positive L- and K- bands. Variable fluorescence at 2 ms (VJ) and 30 ms (VI), absorption flux (ABS/RC), trapped energy flux (TRo/RC), and dissipated energy flux (DIo/RC) increased in Mn-treated leaves, whereas the performance index (PIABS), electron transport flux (ETo/RC), maximum quantum yield (φPo), quantum yield of electron transport (φEo), and probability that an electron moves further than QA- (ψo) decreased. Also, excessive Mn significantly decreased the net photosynthesis rate and increased intercellular CO2 concentration. The results indicated that Mn blocked the electron transfer from the donor side to the acceptor side in PSII, which might be associated with the accumulation of QA-, hence limiting the net photosynthetic rate.

Algorithm and VLSI Architecture Design of Low-Power SPIHT Decoder for mHealth Applications.

A real-time cost and power-efficient (CPE) set partitioning in hierarchical trees (SPIHT) decoder design with low hardware complexity and low-power dissipation is introduced in one-dimension (1-D) wavelet-based quality-assured electrocardiograph (ECG) compression systems for mobile health (mHealth) applications. However, current SPIHT coding architectures are designed for image/video processing. These architectures require a large amount of memory as well as complicated sorting algorithms, which both require time-consuming tasks and are unsuitable for mobile ECG applications. Based on our previously modified SPIHT coding work, which used flags and check bits to reduce memory requirements and coding complexity by merging three search processes into one step. Therefore, to achieve the real-time design goal for mobile ECG applications, in this paper, we first introduce a hardware-oriented SPIHT decoding algorithm that is suitable for decoding the previously presented SPIHT coding work. Accordingly, an appropriate low-power hardware architecture is developed to implement a real-time high-performance and low-cost SPIHT VLSI design for our proposed decoder algorithm, which is appropriate for mobile ECG applications. Using the distinct ECG signals in the MIT-BIH arrhythmia database (sampling rate of 360 Hz), the final simulation and VLSI implementation results reveal that the proposed CPE SPIHT decoder design outperforms the state-of-the-art designs in terms of the average decoding time, the decoding quality, the VLSI speed, and the power consumption. Most importantly, the design can be exploited to a 1-D 1024 × 1 wavelet-based quality-assured ECG data compression system.