Electroacupuncture improves neurovascular unit reconstruction by promoting collateral circulation and angiogenesis

Acupuncture at Shuigou（GV26） shows good clinical efficacy for treating stroke, but its mechanism remains poorly understood. In this study, a cerebral infarction model of ischemia/reperfusion injury received electroacupuncture at GV26（15 Hz and 1 m A, continuous wave [biphasic pulses], for 5 minutes）. Electroacupuncture effectively promoted regional cerebral blood flow on the infarct and non-infarct sides, increased infarct lesions, lectin, and number of blood vessels, upregulated von Willebrand factor and cell proliferation marker Ki67 expression, and diminished neurological severity score. These findings confirm that electroacupuncture at GV26 promotes establishment of collateral circulation and angiogenesis, and improves neurological function.

Bone marrow mesenchymal stem cell therapy regulates gut microbiota to improve post-stroke neurological function recovery in rats

BACKGROUND As a cellular mode of therapy,bone marrow mesenchymal stem cells(BMSCs)are used to treat stroke.However,their mechanisms in stroke treatment have not been established.Recent evidence suggests that regulation of dysregulated gut flora after stroke affects stroke outcomes.AIM To investigate the effects of BMSCs on gut microbiota after ischemic stroke.METHODS A total of 30 Sprague-Dawley rats were randomly divided into three groups,including sham operation control group,transient middle cerebral artery occlusion(MCAO)group,and MCAO with BMSC treatment group.The modified Neurological Severity Score(mNSS),beam walking test,and Morris water maze test were used to evaluate neurological function recovery after BMSC transplantation.Nissl staining was performed to elucidate on the pathology of nerve cells in the hippocampus.Feces from each group of rats were collected and analyzed by 16s rDNA sequencing.RESULTS BMSC transplantation significantly reduced mNSS(P<0.01).Rats performed better in the beam walking test in the BMSC group than in the MCAO group(P<0.01).The Morris water maze test revealed that the BMSC treatment group exhibited a significant improvement in learning and memory.Nissl staining for neuronal damage assessment after stroke showed that in the BMSC group,cells were orderly arranged with significantly reduced necrosis.Moreover,BMSCs regulated microbial structure composition.In rats treated with BMSCs,the abundance of potential short-chain fatty acid producing bacteria and Lactobacillus was increased.CONCLUSION BMSC transplantation is a potential therapeutic option for ischemic stroke,and it promotes neurological functions by regulating gut microbiota dysbiosis.

Effect of Tanshinone IIA on LPS-induced inflammatory response in a ROS-NLRP3 inflammasome dependent manner in RAW264.7 cells

Emerging evidence has demonstrated that Tanshinone IIA (Tan IIA) prevents cardiomyocytes injury, cardiac fibroblasts and atherosclerosis. However, the molecular mechanism underlying the effects of Tan IIA is still unclear. To investigate the role of Tan IIA in inflammatory response in a ROS-NLRP3 inflammasome dependent manner, RAW264.7 cells stimulated with LPS were recruited to produce a cell model of inflammatory response. Our results indicated that the production of NO was significantly increased after stimulated by LPS, and Tan IIA treated significantly decreased the level of NO. The mRNA expression of NLRP3, IL-1β and TNF-α was significantly inhibited by Tan IIA compared with LPS treated cells. The protein expression of NLRP3, IKBα, pp65/p65 and pp38/p38 was significantly decreased by Tan IIA, compared with LPS or LPS+ATP stimulated groups. Meanwhile, Tan IIA significantly inhibited the level of ROS induced by LPS+ATP. And NAC, a ROS inhibitor, could also inhibit the protein expression of NLRP3. Based on these findings, it could be speculated that the mechanism underlying the effect of Tan IIA may involve the regulation of ROS-NF-κB/ P38-NLRP3 pathway. This study further characterized the molecular mechanism of Tan IIA, and provided new thoughts to its clinical therapy.

Non-Stokes drag coefficient in single-particle electrophoresis:New insights on a classical problem

We measured the intrinsic electrophoretic drag coefficient of a single charged particle by optically trapping the particle and applying an AC electric field,and found it to be markedly different from that of the Stokes drag.The drag coefficient,along with the measured electrical force,yield a mobility-zeta potential relation that agrees with the literature.By using the measured mobility as input,numerical calculations based on the Poisson-Nernst-Planck equations,coupled to the Navier-Stokes equation,reveal an intriguing microscopic electroosmotic flow near the particle surface,with a well-defined transition between an inner flow field and an outer flow field in the vicinity of electric double layer’s outer boundary.This distinctive interface delineates the surface that gives the correct drag coefficient and the effective electric charge.The consistency between experiments and theoretical predictions provides new insights into the classic electrophoresis problem,and can shed light on new applications of electrophoresis to investigate biological nanoparticles.

Effect of Rolling Process on Microstructure and Properties of 95CrMo Drill Steel

In order to improve the strength and toughness of 95CrMo steel and explore a short flow process, a direct rolling process was employed, and the effect of finishing rolling process on microstructure and mechanical properties was investigated. The results show that, with the decrease of finishing rolling temperature, inter-lamellar spacing in- creases, the strength as well as hardness has a general increase, and secondary cementite is distributed uniformly but represents a remarkable decrease in size. Based on Hall-Petch type equation, an effective relationship of yield strength and pearlite structure parameters was established. The correlation coefficients between the measured and calculated strength were more than 0.95, which indicated a high reliability of the relationship. By analyzing the individual strength contributions of pearlite structures, yield strength was found to have a more great dependence on pearlite inter-lamellar spacing than colony size.

A Flow Stress Model for High Strength Steels with Low Carbon Bainite Structure

Two kinds of steels （YP960 and YP690） with low carbon bainite structure were designed, and their flow stress and strain hardening exponents were studied. The results showed that, when Hollomon relation was applied to descrihe the flow stress, there were significanl errors between the experimental and calculated points in specimens tempered below 400 ℃, while a high precision was ohserved in samples tempered above 400℃. Whereas, the modijied Voce relation could effectively predici the flow stress as well as the strain hardening exponent at different tempe ring temperatures, which was verified by unbiased estimators such as maximum relative error （MRXE） and average ahsolute relative error （AARE）. Besides, the modified Voee relation was also applied to estimate the maximum uniform strain, and the correlation coefficients （R） between the experimental data and calculated maximum uniform strain were more than 0.91. The high correlation coefficients indicated that the modified Vote relation could effec lively predict the uniform deformation ability of high strength steels with low carbon bainite structure at different tempering temperatures.