219 research outputs found
Dual Arm Coordination in Space Free-Flying Robot
Proceedings of the 1991 IEEE Intematid Conference on Robotics and Automation Sacramento, California - April 199
Induction of human inhibitor of apoptosis protein-2 by shear stress in endothelial cells
AbstractTo disclose the anti-atherosclerotic mechanisms of steady laminar shear stress, we analyzed the expression of human inhibitor of apoptosis protein-2 (HIAP-2), whose gene was selected from a cDNA library of sheared endothelial cells (ECs), on ECs. HIAP-2 was dose-independently and time-dependently induced in ECs by shear stress, regulated at the transcriptional level. HIAP-2 expression was also identified in vivo. Shear stress-mediated inhibition of EC apoptosis was associated with the inhibition of caspase-3 activity, suggesting that the shear stress prevents EC apoptosis via negative regulation of caspase-3 by the increment of HIAP-2
Quantification of Modified Tyrosines in Healthy and Diabetic Human Urine using Liquid Chromatography/Tandem Mass Spectrometry
The quantification of urinary oxidized tyrosines, dityrosine (DiY), nitrotyrosine (NY), bromotyrosine (BrY), and dibromotyrosine (DiBrY), was accomplished by quadruple liquid chromatography-tandem mass spectrometry (LC/MS/MS). The sample was partially purified by solid phase extraction, and was then applied to the LC/MS/MS using multiple-reaction monitoring (MRM) methods. The analysis for the DiY quantification was done first. The residual samples were further butylated with n-butanol/HCl, and the other modified tyrosines were then quantified with isotopic dilution methods. MRM peaks of the modified tyrosines (DiY, NY, BrY, and DiBrY) from human urine were measured and the elution times coincided with the authentic and isotopic standards. The amounts of modified tyrosines in healthy human urine (n = 23) were 8.8 ± 0.6 (DiY), 1.4 ± 0.4 (NY), 3.8 ± 0.3 (BrY), and 0.7 ± 0.1 (DiBrY) µmol/mol of creatinine, respectively. A comparison of the modified tyrosines with urinary 8-oxo-deoxyguanosine, pentosidine, and Nε-(hexanoyl)lysine was also performed. Almost all products, except for NY, showed good correlations with each other. The amounts of the modified tyrosines (NY, BrY, and DiBrY) in the diabetic urine were higher than those in the urine from healthy people
Elimination of Specific miRNAs by Naked 14-nt sgRNAs
tRNase ZL-utilizing efficacious gene silencing (TRUE gene silencing) is a newly developed technology to suppress mammalian gene expression. TRUE gene silencing works on the basis of a unique enzymatic property of mammalian tRNase ZL, which is that it can recognize a pre-tRNA-like or micro-pre-tRNA-like complex formed between target RNA and artificial small guide RNA (sgRNA) and can cleave any target RNA at any desired site. There are four types of sgRNA, 5′-half-tRNA, RNA heptamer, hook RNA, and ∼14-nt linear RNA. Here we show that a 14-nt linear-type sgRNA against human miR-16 can guide tRNase ZL cleavage of miR-16 in vitro and can downregulate the miR-16 level in HEK293 cells. We also demonstrate that the 14-nt sgRNA can be efficiently taken up without any transfection reagents by living cells and can exist stably in there for at least 24 hours. The naked 14-nt sgRNA significantly reduced the miR-16 level in HEK293 and HL60 cells. Three other naked 14-nt sgRNAs against miR-142-3p, miR-206, and miR-19a/b are also shown to downregulate the respective miRNA levels in various mammalian cell lines. Our observations suggest that in general we can eliminate a specific cellular miRNA at least by ∼50% by using a naked 14-nt sgRNA on the basis of TRUE gene silencing
Destruction of mesoscopic chemically modulated domains in single phase high entropy alloy via plastic deformation
Chemically modulated mesoscopic domains in a fcc single phase CrMnFeCoNi equi-atomic high entropy alloy (HEA) are detected by small angle diffraction performed at a synchrotron radiation facility, whereas the mesoscopic domains cannot be detected by conventional X-ray diffraction and 2D mappings of energy dispersive X-ray spectroscopy by scanning electron microscopy and scanning transmission electron microscopy. The mesoscopic domains are deformed and shrieked, and finally destructed by plastic deformation, which is supported by the comprehensive observations/measurements, such as electrical resistivity, Vickers hardness, electron backscattering diffraction, and hard X-ray photoemission spectroscopy. The destruction of the mesoscopic domains causes the decrease in electrical resistivity via plastic deformation, so called K-effect, which is completely opposite to the normal trend of metals. We confirmed that the presence and the size of local chemical ordering or short-range order domains in the single phased HEA, and furthermore, Cr and Mn are related to form the domains
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