The precise role of nucleus pulposus cell proliferation in the pathogenesis of intervertebral disc degeneration remains to be elucidated. Recent findings have revealed that microRNAs, a class of small noncoding RNAs, may regulate cell proliferation in many pathological conditions. Here, we showed that miR-21 was significantly upregulated in degenerative nucleus pulposus tissues when compared with nucleus pulposus tissues that were isolated from patients with idiopathic scoliosis and that miR-10b levels were associated with disc degeneration grade. Moreover, bioinformatics target prediction identified PTEN as a putative target of miR-21. miR-21 inhibited PTEN expression by directly targeting the 3′UTR, and this inhibition was abolished through miR-21 binding site mutations. miR-21 overexpression stimulated cell proliferation and AKT signaling pathway activation, which led to cyclin D1 translation. Additionally, the increase in proliferation and cyclin D1 expression induced by miR-21 overexpression was almost completely blocked by Ly294002, an AKT inhibitor. Taken together, aberrant miR-21 upregulation in intervertebral disc degeneration could target PTEN, which would contribute to abnormal nucleus pulposus cell proliferation through derepressing the Akt pathway. Our study also underscores the potential of miR-21 and the PTEN/Akt pathway as novel therapeutic targets in intervertebral disc degeneration.

Integrating the self-healing property with the shapememory effect is a strategy that extends the service lifetime of shape-memory materials. However, this strategy is inadequate to reshape and recycle through the self-healing property or liquidstate remoldability. For more types of damage, solid-state plasticity is needed as a complementary mechanism to broaden the reprocessing channels of smart materials. In this study, multifunctional thermoplastic polyureas cross-linked by urea hydrogen bonds are prepared, which possess the multipathway remodeling property. The shape transition can be triggered after heating above 65 °C. The synergistic effect of dynamic disulfide bonds and hydrogen bonds causes the thermoplastic polyureas to possess characteristics similar to those of associative covalent adaptable networks. Thus, the polyureas can repair the damage or reconfigure the shape at 75 °C in 15 min by solid-state plasticity, instead of going into a viscous flow state. Soft grippers with various shapes are prepared by integration of solid-state plasticity, and the structure and function of the grippers can be repaired. The integration of solid-state plasticity and the self-healing property broadens the paths of shape-memory polymers in recyclability and reshapability.

How to implant a stent in the body through minimally invasive operation and track its location in real time is still a challenge. Herein, a near-infrared (NIR) light-triggered shape-memory polymer...

No abstract

No abstract

No abstract

The Unified Scaling Law for Earthquakes (USLE), that generalizes the GutenbergRichter recurrence relation, has evident implications since any estimate of seismic hazard depends on the size of territory that is used for investigation, averaging, and extrapolation into the future. Therefore, the hazard may differ dramatically when scaled down to the proportion of the area of interest (e.g. a city) from the enveloping area of investigation. In fact, given the observed patterns of distributed seismic activity the results of multi-scale analysis embedded in USLE approach demonstrate that traditional estimations of seismic hazard and risks for cities and urban agglomerations are usually underestimated. Moreover, the USLE approach provides a significant improvement when compared to the results of probabilistic seismic hazard analysis, e.g. the maps resulted from the Global Seismic Hazard Assessment Project (GSHAP). In this paper, we apply the USLE approach to evaluating seismic hazard and risks to population of the three territories of different size representing a sub-continental and two different regional scales of analysis, i.e. the Himalayas and surroundings, Lake Baikal, and Central China regions.

Our follow-up shows that ACDR is an effective treatment for post-ACDF ASD. It can maintain the ROMs of the replaced segment as well as the adjacent unfused segment.