VIBRATION OF CANTILEVERS WITH ROUGH SURFACES

We study the effect of surface roughness on the resonance frequency of micro-cantilever sensors. The analysis demonstrates that surface roughness can enhance, decrease or even annul the effect of surface stress on the resonance frequency, depending on the surface inclination angle and the Poisson ratio of the coating film on the cantilever.

Role of autoreactive Tc17 cells in the pathogenesis of experimental autoimmune encephalomyelitis

Background:The pathogenesis of multiple sclerosis(MS)and experimental autoimmune encephalomyelitis(EAE-an animal model of MS)is primarily mediated by T cells.However,recent studies have only focused on interleukin(IL)-17-secreting CD4^(+)T-helper cells,also known as Th17 cells.This study aimed to compare Th17 cells and IL-17-secreting CD8^(+)T-cytotoxic cells(Tc17)in the context of MS/EAE.Methods:Female C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein peptides 35-55(MOG35-55),pertussis toxin,and complete Freund's adjuvant to establish the EAE animal model.T cells were isolated from the spleen(12-14 days postimmunization).CD4^(+)and CD8^(+)T cells were purified using isolation kit and then differentiated into Th17 and Tc17,respectively,using MOG35-55 and IL-23.The secretion levels of interferon-(IFN-γ)and IL-17 were measured via enzyme-linked immunosorbent assay using cultured CD4^(+)and CD8^(+)T cell supernatants.The pathogenicity of Tc17 and Th17 cells was assessed through adoptive transfer(tEAE),with the clinical course assessed using an EAE score(0-5).Hematoxylin and eosin as well as Luxol fast blue staining were used to examine the spinal cord.Purified CD8^(+)CD3^(+)and CD4^(+)CD3^(+)cells differentiated into Tc17 and Th17 cells,respectively,were stimulated with MOG35-55 peptide for proliferation assays.Results:The results showed that Tc17 cells(15,951±19855VS.55,709±4196cpm;p<0.050)exhibited a weaker response to highest dose(20μg/mL)MOG35-55 than Th17 cells.However,this response was not dependent on Th17 cells.After the 48h stimulation,at the highest dose(20μg/mL)of MOG35-55.Tc17 cells secreted lower levels of IFN-(280.00±15.00vs.556.67±15.28pg/mL,p<0.050)and IL-17(102.67±5.86 pg/mL vs.288.33±12.58 pg/mL;p<0.050)than Th17 cells.Similar patterns were observed for IFN-γsecretion at 96 and 144h.Furthermore,Tc17 cell-induced tEAE mice exhibited similar EAE scores to Th17 cell-induced tEAE mice and also showed similar inflammation and demyelination.Conclusion:The degree of pathogenicity of Tc17 cells in EAE is lower than that of Th17 cells.Future investigation on different immune cells and EAE models is warranted to determine the mechanisms underlying MS.

Numerical simulation of cavitating flow around a slender body with slip boundary condition

In this paper, we perform a numerical simulation of the cavitating flow around an underwater hemispherical-head slender body running at a high speed. For the first time, the slip boundary condition is introduced into this problem, and we find that the slip boundary condition has a big influence on the cavitation in the flow-separation zone. By simulating the cavitating flow under different cavitation numbers, we demonstrate that the slip boundary condition can effectively reduce the intensity of cavitation, as represented by the length of cavitation bubbles. The present paper provides a new method for utilization of new surface materials to control the cavitation on the underwater moving objects.