Nursing Students’ Views on Rural Nursing Practice in China

Yuexian Tao 한국간호과학회 2015 한국간호과학회 학술대회 Vol.2015 No.10

Insulin-like Growth Factor-1 Receptor Dictates Beneficial Effects of Treadmill Training by Regulating Survival and Migration of Neural Stem Cell Grafts in the Injured Spinal Cord

황동훈,박희환,신해영,Yuexian Cui,김병곤 한국뇌신경과학회 2018 Experimental Neurobiology Vol.27 No.6

Survival and migration of transplanted neural stem cells (NSCs) are prerequisites for therapeutic benefits in spinal cord injury. We have shown that survival of NSC grafts declines after transplantation into the injured spinal cord, and that combining treadmill training (TMT) enhances NSC survival via insulin-like growth factor-1 (IGF-1). Here, we aimed to obtain genetic evidence that IGF-1 signaling in the transplanted NSCs determines the beneficial effects of TMT. We transplanted NSCs heterozygous (+/-) for Igf1r, the gene encoding IGF-1 receptor, into the mouse spinal cord after injury, with or without combining TMT. We analyzed the influence of genotype and TMT on locomotor recovery and survival and migration of NSC grafts. In vitro experiments were performed to examine the potential roles of IGF-1 signaling in the migratory ability of NSCs. Mice receiving +/- NSC grafts showed impaired locomotor recovery compared with those receiving wild-type (+/+) NSCs. Locomotor improvement by TMT was more pronounced with +/+ grafts. Deficiency of one allele of Igf1r significantly reduced survival and migration of the transplanted NSCs. Although TMT did not significantly influence NSC survival, it substantially enhanced the extent of migration for only +/+ NSCs. Cultured neurospheres exhibited dynamic motility with cytoplasmic protrusions, which was regulated by IGF-1 signaling. IGF-1 signaling in transplanted NSCs may be essential in regulating their survival and migration. Furthermore, TMT may promote NSC graft-mediated locomotor recovery via activation of IGF-1 signaling in transplanted NSCs. Dynamic NSC motility via IGF-1 signaling may be the cellular basis for the TMT-induced enhancement of migration.

High-mobility group box-1 as an autocrine trophic factor in white matter stroke

Choi, Jun Young,Cui, Yuexian,Chowdhury, Samma Tasneem,Kim, Byung Gon National Academy of Sciences 2017 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.114 No.25

<P>Maintenance of white matter integrity in health and disease is critical for a variety of neural functions. Ischemic stroke in the white matter frequently results in degeneration of oligodendrocytes (OLs) and myelin. Previously, we found that toll-like receptor 2 (TLR2) expressed in OLs provides cell-autonomous protective effects on ischemic OL death and demyelination in white matter stroke. Here, we identified high-mobility group box-1 (HMGB1) as an endogenous TLR2 ligand that promotes survival of OLs under ischemic stress. HMGB1 rapidly accumulated in the culture medium of OLs exposed to oxygen-glucose deprivation (OGD). This conditioned medium exhibited a protective activity against ischemic OL death that was completely abolished by immunodepletion of HMGB1. Knockdown of HMGB1 or application of glycyrrhizin, a specific HMGB1 inhibitor, aggravated OGD-induced OL death, and recombinant HMGB1 application reduced the extent of OL death in a TLR2-dependent manner. We confirmed that cytosolic translocation of HMGB1 and activation of TLR2-mediated signaling pathways occurred in a focal white matter stroke model induced by endothelin-1 injection. Animals with glycyrrhizin coinjection showed an expansion of the demyelinating lesion in a TLR2-dependent manner, accompanied by aggravation of sensorimotor behavioral deficits. These results indicate that HMGB1/TLR2 activates an autocrine trophic signaling pathways in OLs and myelin to maintain structural and functional integrity of the white matter under ischemic conditions.</P>

CCL2 Mediates Neuron–Macrophage Interactions to Drive Proregenerative Macrophage Activation Following Preconditioning Injury

Kwon, Min Jung,Shin, Hae Young,Cui, Yuexian,Kim, Hyosil,Thi, Anh Hong Le,Choi, Jun Young,Kim, Eun Young,Hwang, Dong Hoon,Kim, Byung Gon Society for Neuroscience 2015 The Journal of neuroscience Vol.35 No.48

<P>CNS neurons in adult mammals do not spontaneously regenerate axons after spinal cord injury. Preconditioning peripheral nerve injury allows the dorsal root ganglia (DRG) sensory axons to regenerate beyond the injury site by promoting expression of regeneration-associated genes. We have previously shown that peripheral nerve injury increases the number of macrophages in the DRGs and that the activated macrophages are critical to the enhancement of intrinsic regeneration capacity. The present study identifies a novel chemokine signal mediated by CCL2 that links regenerating neurons with proregenerative macrophage activation. Neutralization of CCL2 abolished the neurite outgrowth activity of conditioned medium obtained from neuron-macrophage cocultures treated with cAMP. The neuron-macrophage interactions that produced outgrowth-promoting conditioned medium required CCL2 in neurons and CCR2/CCR4 in macrophages. The conditioning effects were abolished in CCL2-deficient mice at 3 and 7 d after sciatic nerve injury, but CCL2 was dispensable for the initial growth response and upregulation of GAP-43 at the 1 d time point. Intraganglionic injection of CCL2 mimicked conditioning injury by mobilizing M2-like macrophages. Finally, overexpression of CCL2 in DRGs promoted sensory axon regeneration in a rat spinal cord injury model without harmful side effects. Our data suggest that CCL2-mediated neuron-macrophage interaction plays a critical role for amplification and maintenance of enhanced regenerative capacity by preconditioning peripheral nerve injury. Manipulation of chemokine signaling mediating neuron-macrophage interactions may represent a novel therapeutic approach to promote axon regeneration after CNS injury.</P>

Signal parameter estimation through hierarchical conjugate gradient least squares applied to tensor decomposition

Liu, Long,Wang, Ling,Xie, Jian,Wang, Yuexian,Zhang, Zhaolin Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.6

A hierarchical iterative algorithm for the canonical polyadic decomposition (CPD) of tensors is proposed by improving the traditional conjugate gradient least squares (CGLS) method. Methods based on algebraic operations are investigated with the objective of estimating the direction of arrival (DoA) and polarization parameters of signals impinging on an array with electromagnetic (EM) vector-sensors. The proposed algorithm adopts a hierarchical iterative strategy, which enables the algorithm to obtain a fast recovery for the highly collinear factor matrix. Moreover, considering the same accuracy threshold, the proposed algorithm can achieve faster convergence compared with the alternating least squares (ALS) algorithm wherein the highly collinear factor matrix is absent. The results reveal that the proposed algorithm can achieve better performance under the condition of fewer snapshots, compared with the ALS-based algorithm and the algorithm based on generalized eigenvalue decomposition (GEVD). Furthermore, with regard to an array with a small number of sensors, the observed advantage in estimating the DoA and polarization parameters of the signal is notable.

Performance of coated cutting tools in turning a malleable cast iron

Tingjie Zhang,Chengyong Wang,Hua Yuan,Qimin Wang,Yuexian Song,Yingning Hu 한국생산제조학회 2014 한국생산제조시스템학회 학술발표대회 논문집 Vol.2014 No.9(2)

Effect of surface roughness on the flotation separation of hematite from fine quartz

Zhanglei Zhu,Zhen Li,Wanzhong Yin,Bin Yang,Ningning Zhang,Jinzhou Qu,Songjiang Chen,Jing Chang,Yuexian Yu,Lijun Liu 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

Although the effect of surface roughness on the floatability of a single mineral has been investigatedextensively, a systematic study for the effect of surface roughness on the flotation separation of differentminerals, e.g., flotation recovery, has never been dwelled. To fulfill this gap, in this study, the effect of surfaceroughness on the flotation separation of hematite from quartz was investigated with a series ofexperiments and detections. Micro-flotation experiments demonstrated that hematite particles withhigher roughness resulted in higher recoveries for both hematite and quartz, but the improvement ofhematite recovery was more significant, which promoted the flotation separation of hematite fromquartz with a higher separation index (SI). Adhesion force measurements revealed that after interactingwith 125 mg/L sodium oleate at pH 9, increasing nano-scaled roughness improved the hydrophobicity ofhematite surface, and reduced the adhesion force of water droplet on hematite surface. Scanning ElectronMicroscope – Energy Dispersive Spectrometer observations confirmed that increasing nano-scaled roughnessincreased the number of fine quartz particles coating on hematite surface. Combined with the analysisof adhesion of water droplet and observation of fine particles coating on hematite surface, the effectof surface roughness on minerals flotation separation could be better understood.