Engineering nerve guidance conduits with three-dimenisonal bioprinting technology for long gap peripheral nerve regeneration

Nerve guidance conduits (NGCs) are tubular structures that are used to bridge the gap of a severed nerve, thereby acting as a guide and protective micro-environment for the regenerating axons and as a barrier against the in-growth of scar-forming tissue. In the last few decades, the concept of NGCs has evolved from a research tool to investigate nerve regeneration into a translational product that is now being used clinically as an alternative for autologous nerve graft repair, due to their availability and ease of fabrication.

3D printed nerve guidance channels: computer-aided control of geometry, physical cues, biological supplements and gradients

Nerve guidance channels for peripheral nerve injury： Over the past decade, nerve guidance channels （NGCs） have emerged as a promising technology for regenerating gap injuries in peripheral nerves. Nerve gap injuries resulting from neurodegeneration and trauma, such as car accidents and battlefield wounds, affect hun- dreds of thousands of people annually. Motivated by suboptimal results obtained with the current gold standard of autologous grafting （i.e., autografts）, various commercially available NGCs composed of synthetic and biomaterials are now alternatively available （Jia et al., 2014; Jones et al., 2016）.

Treating peripheral nerve injury-induced spinal cord degeneration and neuropathic pain with peripherally administrated stem cells

Peripheral nerve injury(PNI)causes sensory and motor deficits as well as neuropathic pain,which seriously impacts patient quality of life(Jiang et al.,2017).Morphological and molecular changes in the spinal cord and dorsal root ganglia(DRG),such as neuronal cell death,nerve fiber degeneration,and glial activation,are strongly associated with PNI-induced pathological syndromes.

NUMERICAL ANALYSIS OF A BDF2 MODULAR GRAD-DIV STABILITY METHOD FOR THE STOKES/DARCY EQUATIONS

In this paper,a BDF2 modular grad-div algorithm for the Stokes/Darcy model is constructed.This method not only effectively avoids solver breakdown,but also increases computational efficiency for increasing parameter values.Herein,complete stability and error analysis are provided.Finally,some numerical tests are proposed to justify the theoretical analysis.

Elevated nuclear phospho-eIF4E body levels are associated with tumor progression and poor prognosis for acute myeloid leukemia

Uncontrolled proliferation is a hallmark of cancer cells,yet the molecular mechanisms that contribute to this proliferation are unclear.Therapeutic treatment of cancer is suboptimal in many cases,with no accurate index by which to evaluate the success of treatment or patient prognosis.In this study,we explored the protein levels of nuclear phospho-eIF4E in acute myeloid leukemia(AML)cell lines and primary leukemia samples by Western blot and immunofluorescence and as well analyzed transcriptomes by RNA-seq.We found nuclear phospho-eIF4E,an exporter of oncogenic mRNAs,to be abundant in AML.Further,nuclear phospho-eIF4E abundance was significantly associated with tumor burden as well as the response of AML patients to chemotherapy.The results demonstrate“massive clustering and export of oncogenic mRNAs to the translation machinery”by highly abundant RNA-nuclear phospho-eIF4E bodies.This is an efficient mechanism that may drive the proliferation of cancer cells.Herein,nuclear phospho-eIF4E bodies were identified as potential markers of AML,which may be useful for prognosis and as targets for cancer therapy.

Pharmacological induced target temperature management after cardiac arrest： the capsaicinoids

Cardiac or respiratory arrest lasting only a few minutes can inflict grave harm on numerous bodily organs, not least of all, the brain. Neurocognitive deficits, which are often severe and profoundly life altering, remain a major source of morbidity among survivors.

High-SNR Staining Algorithm for One-Way Wave Equation-Based Modelling and Imaging

Staining algorithms based on two-way wave equation migration methods have been applied to improve the signal-to-noise ratio(SNR)of poorly illuminated structures such as those in subsalt zones.In regular staining algorithms,when a source wavefield reaches the stained area that is associated with the target structures,a new wavefield called stained wavefield is excited,and this stained wavefield forward extrapolates synchronously with the real source wavefield.The forward-extrapolated stained and real source wavefields are cross-correlated with the backward-extrapolated receiver wavefield,and we obtain the stained and the real reverse time migration(RTM)images.The staining algorithms for RTM can suppress the noise of non-target regions and obtain high SNR images of the target structures.Whereas RTM methods are limited by the low computational efficiency and SNR,by contrast,one-way wave equation migration(OWEM)methods have the advantages of high efficiency and no interference from multiples.Thus,we developed a new staining method based on the generalised screen propagator(GSP)as a case of OWEM methods for subsalt imaging.Furthermore,a new stained wavefield called stained receiver wavefield is proposed here,forming two new staining strategies for seismic imaging,in which forward-propagated source and backward-propagated receiver wavefields can be conveniently selected to be stained at the stained area.Numerical experiments demonstrated that this staining GSP method is more effective in improving the SNR of subsalt structures compared to conventional GSP migration and RTM methods;moreover,these new staining strategies as applied to the OWEM methods can greatly improve the SNR of weakly illuminated structures in subsalt zones,in comparison with regular staining algorithms for one-way methods.

Evolution of undeformed chip thickness and grinding forces in grinding of K4002 nickel-based superalloy using corundum abrasive wheels

The undeformed chip thickness and grinding force are key parameters for revealing the material removal mechanism in the grinding process.However,they are difficult to be well expressed due to the ununiformed protrusion height and random position distribution of abrasive grains on the abrasive wheel surface.This study investigated the distribution of undeformed chip thickness and grinding force considering the non-uniform characteristics of abrasive wheel in the grinding of K4002 nickel-based superalloy.First,a novel grinding force model was established through a kinematic-geometric analysis and a grain-workpiece contact analysis.Then,a series of grinding experiments were conducted for verifying the model.The results indicate that the distribution of undeformed chip thickness is highly consistent with the Gaussian distribution formula.The increase in the grinding depth mainly leads to an increase in the average value of Gaussian distribution.On the contrary,the increase in the workpiece infeed speed or the decrease in the grinding speed mainly increases the standard deviation of Gaussian distribution.The average and maximum errors of the grinding force model are 4.9%and 14.6%respectively,indicating that the model is of high predication accuracy.