Strain sensor using stress-magnetoresistance effect of Ni-Fe/Mn-Ir exchange-coupled magnetic film

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in JOURNAL OF APPLIED PHYSICS. 107(9):09E718 (2010) and may be found at https://doi.org/10.1063/1.3362902 .A strain sensor using a stress-magnetoresistance effect of a Ni-Fe/Mn-Ir exchange-coupled magnetic film was fabricated and evaluated. The stress magnetoresistance is used in the inverse magnetostrictive effect and the magnetoresistance effect in the magnetic film since an external stress is changed into an electric resistance in it. A compressive stress was measured by the strain sensor with a Mn-Ir (10 nm)/Ni-Fe (50 nm)/Ru (1 nm) exchange-coupled film. The change in resistivity Delta rho/rho is proportional to the applied compressive stress sigma for sigma <= 50 MPa in the strain sensor. When increasing Ni-Fe layer thickness in the strain sensor, a gauge factor increased.ArticleJOURNAL OF APPLIED PHYSICS. 107(9):09E718 (2010)journal articl

Mn–Ir/Fe–Si exchange-coupled multilayer film with plural ferromagnetic resonance absorptions for wideband noise filter

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in JOURNAL OF APPLIED PHYSICS. 99(8):08M309 (2006) and may be found at https://doi.org/10.1063/1.2177208 .ArticleJOURNAL OF APPLIED PHYSICS. 99(8):08M309 (2006)journal articl

Mn–Ir∕Fe–Si exchange-coupled multilayer film with plural ferromagnetic resonance absorptions for wideband noise filter

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in JOURNAL OF APPLIED PHYSICS. 99(8):08M309 (2006) and may be found at https://doi.org/10.1063/1.2177208 .ArticleJOURNAL OF APPLIED PHYSICS. 99(8):08M309 (2006)journal articl

Strain sensor using stress-magnetoresistance effect of Ni–Fe/Mn–Ir exchange-coupled magnetic film

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in JOURNAL OF APPLIED PHYSICS. 107(9):09E718 (2010) and may be found at https://doi.org/10.1063/1.3362902 .A strain sensor using a stress-magnetoresistance effect of a Ni-Fe/Mn-Ir exchange-coupled magnetic film was fabricated and evaluated. The stress magnetoresistance is used in the inverse magnetostrictive effect and the magnetoresistance effect in the magnetic film since an external stress is changed into an electric resistance in it. A compressive stress was measured by the strain sensor with a Mn-Ir (10 nm)/Ni-Fe (50 nm)/Ru (1 nm) exchange-coupled film. The change in resistivity Delta rho/rho is proportional to the applied compressive stress sigma for sigma <= 50 MPa in the strain sensor. When increasing Ni-Fe layer thickness in the strain sensor, a gauge factor increased.ArticleJOURNAL OF APPLIED PHYSICS. 107(9):09E718 (2010)journal articl

Magnetic and electronic properties of bimagnetic materials comprising cobalt particles within hollow silica decorated with magnetite nanoparticles

Bimagnetic materials were fabricated by decorating the external surface of rattle-type hollow silica microspheres (which themselves contain metallic cobalt nanoparticles) with magnetite nanoparticles; thus, each magnetic substance was spatially isolated by the silica shell. The amount of magnetite decoration on the co-occluded hollow silica was varied from 1 to 17 mass %. Magnetic and electronic properties of the resulting bimagnetic materials were characterized by superconducting quantum interference device measurements and X-ray absorption spectroscopy, respectively. The ferrous iron in the bimagnetic sample was slightly more oxidized than in the magnetite reference, probably from some charge-transfer because of the SiO2 surface contact, although the overall oxidation state of the samples is very similar to that of magnetite. The temperature dependence of the sample magnetization recorded with Zero Field Cooling and Field Cooling resulted in blocking temperatures for the bimagnetic materials that were close to that of magnetite nanoparticles (176K) and were lower than that for the bare Co-occluded hollow silica (which was above room temperature). Values of coercive force and exchange bias at 300K became quite small after decoration with only minimal amounts of magnetite nanoparticles (1-3 mass %) and were lower than those of magnetite. This is the first example of enhancing superparamagnetism by spatial separation of both Co and magnetite magnetic nanoparticles using a thin wall of diamagnetic silica.ArticleJOURNAL OF APPLIED PHYSICS. 114(12):124304 (2013)journal articl

Magnetic and electronic properties of bimagnetic materials comprising cobalt particles within hollow silica decorated with magnetite nanoparticles

Bimagnetic materials were fabricated by decorating the external surface of rattle-type hollow silica microspheres (which themselves contain metallic cobalt nanoparticles) with magnetite nanoparticles; thus, each magnetic substance was spatially isolated by the silica shell. The amount of magnetite decoration on the co-occluded hollow silica was varied from 1 to 17 mass %. Magnetic and electronic properties of the resulting bimagnetic materials were characterized by superconducting quantum interference device measurements and X-ray absorption spectroscopy, respectively. The ferrous iron in the bimagnetic sample was slightly more oxidized than in the magnetite reference, probably from some charge-transfer because of the SiO2 surface contact, although the overall oxidation state of the samples is very similar to that of magnetite. The temperature dependence of the sample magnetization recorded with Zero Field Cooling and Field Cooling resulted in blocking temperatures for the bimagnetic materials that were close to that of magnetite nanoparticles (176K) and were lower than that for the bare Co-occluded hollow silica (which was above room temperature). Values of coercive force and exchange bias at 300K became quite small after decoration with only minimal amounts of magnetite nanoparticles (1-3 mass %) and were lower than those of magnetite. This is the first example of enhancing superparamagnetism by spatial separation of both Co and magnetite magnetic nanoparticles using a thin wall of diamagnetic silica.ArticleJOURNAL OF APPLIED PHYSICS. 114(12):124304 (2013)journal articl

Immunological analysis of a Lactococcus lactis-based DNA vaccine expressing HIV gp120

For reasons of efficiency Escherichia coli is used today as the microbial factory for production of plasmid DNA vaccines. To avoid hazardous antibiotic resistance genes and endotoxins from plasmid systems used nowadays, we have developed a system based on the food-grade Lactococcus lactis and a plasmid without antibiotic resistance genes. We compared the L. lactis system to a traditional one in E. coli using identical vaccine constructs encoding the gp120 of HIV-1. Transfection studies showed comparable gp120 expression levels using both vector systems. Intramuscular immunization of mice with L. lactis vectors developed comparable gp120 antibody titers as mice receiving E. coli vectors. In contrast, the induction of the cytolytic response was lower using the L. lactis vector. Inclusion of CpG motifs in the plasmids increased T-cell activation more when the E. coli rather than the L. lactis vector was used. This could be due to the different DNA content of the vector backbones. Interestingly, stimulation of splenocytes showed higher adjuvant effect of the L. lactis plasmid. The study suggests the developed L. lactis plasmid system as new alternative DNA vaccine system with improved safety features. The different immune inducing properties using similar gene expression units, but different vector backbones and production hosts give information of the adjuvant role of the silent plasmid backbone. The results also show that correlation between the in vitro adjuvanticity of plasmid DNA and its capacity to induce cellular and humoral immune responses in mice is not straight forward

Genetic drivers of heterogeneity in type 2 diabetes pathophysiology

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes1,2 and molecular mechanisms that are often specific to cell type3,4. Here, to characterize the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study data from 2,535,601 individuals (39.7% not of European ancestry), including 428,452 cases of T2D. We identify 1,289 independent association signals at genome-wide significance (P &lt; 5 × 10-8) that map to 611 loci, of which 145 loci are, to our knowledge, previously unreported. We define eight non-overlapping clusters of T2D signals that are characterized by distinct profiles of cardiometabolic trait associations. These clusters are differentially enriched for cell-type-specific regions of open chromatin, including pancreatic islets, adipocytes, endothelial cells and enteroendocrine cells. We build cluster-specific partitioned polygenic scores5 in a further 279,552 individuals of diverse ancestry, including 30,288 cases of T2D, and test their association with T2D-related vascular outcomes. Cluster-specific partitioned polygenic scores are associated with coronary artery disease, peripheral artery disease and end-stage diabetic nephropathy across ancestry groups, highlighting the importance of obesity-related processes in the development of vascular outcomes. Our findings show the value of integrating multi-ancestry genome-wide association study data with single-cell epigenomics to disentangle the aetiological heterogeneity that drives the development and progression of T2D. This might offer a route to optimize global access to genetically informed diabetes care.</p