249,093 research outputs found
Effects of HO-1 overexpression on mitochondrial dysfunction and autophagy level in Lv-HO-1-H9c2 cells with H/R model.
No full text(A) Cell viability was measured using the CCK-8 assay. The data are presented as means ± SE (N = 5). **p<0.01 vs corresponding Normoxia group; #p<0.05, vs corresponding Lv-scramble group. (B) Real-time quantitative PCR (RT q-PCR) analyses of HO-1 mRNA expression in lv-HO-1 H9c2 cells subjected to H/R relative to GAPDH expression (n = 3 wells per group). **p<0.01 vs. the normoxia group. (C) H/R-induced HO-1, p62, and LC-3 protein expression analyzed using western blots of lv-HO-1 H9c2 cells. GAPDH was used as a loading control (n = 3 wells per group). ##p<0.01 vs corresponding Lv-scramble group; ***p<0.001 vs. the corresponding normoxia group. (D) Representative confocal microscopy images and quantitative analysis of autophagosomes from 15 fields (n = 3 hearts per group). Scale bar = 500 nm. *p<0.05 vs. the corresponding normoxia group; ##p<0.01, vs corresponding Lv-scramble group. H/R, Hypoxia/reoxygenation; HO-1, heme oxygenase-1. (E,F) Flow cytometry detection of changes in JC-1 fluorescence color reflects changes in the mitochondrial membrane potential and mitochondrial ROS levels. #p<0.05, vs corresponding Lv-scramble group; **p<0.01 vs corresponding Normoxia group, #p<0.05, vs corresponding Lv-scramble group. (G) The apoptosis rate of the four groups. Cell identification and detection of apoptosis. **p<0.01 vs corresponding Normoxia group; ##p<0.01, vs corresponding Lv-scramble group.</p
HO-1 and HIF-1α are expressed in the peri-infarct region of the ischemic mouse brain.
No full text(A) Representative image of the TTC stained regions (a, contralateral region; b, peri-infarct region; c, infarct region) in a mouse subjected to 2 h ischemia and 24 h reperfusion (I/R) (n = 3 per group). (B) DAB staining observed as brown color in the peri-infarct region (b) in wild-type (WT) and HO-1+/- mice. Scale bars = 20 μm. (C) Expression of target proteins was determined in brain tissues using western blot analysis, and their levels were quantified (n = 5 per group). **P D) WT and HO-1+/- mice were subjected to I/R, and the brain sections (a, contralateral region; b, peri-infarct region; c, infarct region) were stained with the indicated antibodies (n = 4 per group). Images are representative from three individual tissues.</p
Cooling rates of neutron stars and the young neutron star in the Cassiopeia A supernova remnant
No full textWe explore the thermal state of the neutron star in the Cassiopeia A supernova remnant using the recent result of Ho & Heinke that the thermal radiation of this star is well described by a carbon atmosphere model and the emission comes from the entire stellar surface. Starting from neutron star cooling theory, we formulate a robust method to extract neutrino cooling rates of thermally relaxed stars at the neutrino cooling stage from observations of thermal surface radiation. We show how to compare these rates with the rates of standard candles – stars with non-superfluid nucleon cores cooling slowly via the modified Urca process. We find that the internal temperature of standard candles is a well-defined function of the stellar compactness parameter x=rg/R, irrespective of the equation of state of neutron star matter (R and rg are circumferential and gravitational radii, respectively). We demonstrate that the data on the Cassiopeia A neutron star can be explained in terms of three parameters: f?, the neutrino cooling efficiency with respect to the standard candle; the compactness x; and the amount of light elements in the heat-blanketing envelope. For an ordinary (iron) heat-blanketing envelope or a low-mass (? 10?13 M?) carbon envelope, we find the efficiency f?? 1 (standard cooling) for x? 0.5 and f?? 0.02 (slower cooling) for a maximum compactness x? 0.7. A heat blanket containing the maximum mass (?10?8 M?) of light elements increases f? by a factor of 50. We also examine the (unlikely) possibility that the star is still thermally non-relaxe
Structure and magnetic properties of ScFe6Ga6-type RCo5Ga7 (R = Y, Tb, Dy, Ho and Er)
No full textThe structure and magnetic properties of the RCo5Ga7 (R = Y, Tb, Dy, Ho and Er) compounds with the ScFe6Ga6-type structure have been studied. The stability of RCo5Ga7 is closely related with the ratio of the metal radii R-RE/R-(Co,R-Ga). With R-RE/R-(Co,R-Ga) less than or equal to 1.36, the compounds can be stabilized in the ScFe6Ga6-type structure. The lattice of RCo5Ga7 shrinks as the atomic order of R increases, and it is consistent with the lanthanide contraction. The structure analysis based on X-ray diffraction patterns reveals that in the orthorhombic RCo5Ga7 (Immm), R occupies the 2a site, and Co enters into the 8k and the 4h sites, and Ga is at the 4e, 4f, 4g, 4h and 8k sites. The interatomic distances and the coordination numbers of RCo5Ga7 are provided from the refinement results. The short interatomic distance (less than 2.480 Angstrom) between the Co ions results in the negative magnetic interaction, which does not favor ferromagnetic ordering. The magnetic moment of YCo5Ga7 is absent, and RCo5Ga7 (R = Tb, Dy, Ho and Er) may have long-range magnetic ordering with the paramagnetic Curie temperature lower than 5 K. (C) 2004 Elsevier Inc. All rights reserved
Structural and magnetic properties of R(FexMn1-x)12 (R = Ho,Y)
No full textThe crystallographic structures and magnetic properties of R(FexMn1-x)(12) (R=Ho,Y; x=0, 0.2, 0.5, 0.6, 0.7) have been studied using powder neutron diffraction and magnetic measurements. These compounds crystallize in a ThMn12-type structure. The rare earths occupy the 2a sites, and Fe and Mn atoms are distributed on three nonequivalent sites: 8i, 8i, and 8f. The Mn and Fe atoms are found to exhibit strong site preferences, with the 8i sites favoring Mn atoms and the 8f sites favoring Fe atoms. Ho(Fe,Mn)(12) compounds show a noncollinear magnetic structure within the Mn(,Fe) sublattice. Spin-glass-like behavior has been observed in these two series. There are two characteristic temperatures for the Ho(Mn1-xFex)(12); one corresponding to the compensation of the ordered Ho and (Mn,Fe) magnetic moments, and the other to the ordering of the (Mn,Fe) lattice. The uncommon feature of two ordering temperatures in this compound is due to the weak rare-earth (R) transition-metal (T) interaction. The addition of Fe substantially modifies the magnetic interactions, thus increasing the ordering temperature and changing the type of magnetic order of the (Mn,Fe) sublattice.Physics, Condensed MatterSCI(E)15ARTICLE6null6
Study of Ho-doped Bi2Te3 topological insulator thin films
No full textThis publication arises from research funded by the John Fell Oxford University Press (OUP) Research Fund and the Research Complex at Harwell is acknowledged for their hospitality. This work was supported by a DARPA MESO project (No. N66001-11-1-4105). S.E.H. was supported by the VPGE (Stanford University). L.C.M. and A.A.B. acknowledge partial financial support from EPSRC (UK) through a Doctoral Training Award. Diamond Light Source is acknowledged for beamtime on I10 (proposal SI10207).Breaking time-reversal symmetry through magnetic doping of topological insulators has been identified as a key strategy for unlocking exotic physical states. Here, we report the growth of Bi2Te3 thin films doped with the highest magnetic moment element Ho. Diffraction studies demonstrate high quality films for up to 21% Ho incorporation. Superconducting quantum interference device magnetometry reveals paramagnetism down to 2 K with an effective magnetic moment of ∼5 μB/Ho. Angle-resolved photoemission spectroscopy shows that the topological surface state remains intact with Ho doping, consistent with the material's paramagnetic state. The large saturation moment achieved makes these films useful for incorporation into heterostructures, whereby magnetic order can be introduced via interfacial coupling.Peer reviewe
Magnetic properties of RIrSi (R = Tb, Dy, and Ho) compounds
No full textThe magnetic data for the polycrystalline samples of RIrSi (R = Tb, Dy and Ho) compounds are reported. These compounds are antiferromagnets with the Néel temperatures equal to 32 K (R = Tb), 7.0 K (R = Dy) and 4.8 K (R = Ho), respectively. The external magnetic field induces the one step for TbIrSi and two step for DyIrSi and HoIrSi metamagnetic phase transitions. The values of the critical field as Néel temperatures decrease with increase of the number of 4f electrons. The magnetic phase diagrams (H, T) are determined
HMOX1 gene promoter alleles and high HO-1 levels are associated with severe malaria in Gambian children.
No full textHeme oxygenase 1 (HO-1) is an essential enzyme induced by heme and multiple stimuli associated with critical illness. In humans, polymorphisms in the HMOX1 gene promoter may influence the magnitude of HO-1 expression. In many diseases including murine malaria, HO-1 induction produces protective anti-inflammatory effects, but observations from patients suggest these may be limited to a narrow range of HO-1 induction, prompting us to investigate the role of HO-1 in malaria infection. In 307 Gambian children with either severe or uncomplicated P. falciparum malaria, we characterized the associations of HMOX1 promoter polymorphisms, HMOX1 mRNA inducibility, HO-1 protein levels in leucocytes (flow cytometry), and plasma (ELISA) with disease severity. The (GT)(n) repeat polymorphism in the HMOX1 promoter was associated with HMOX1 mRNA expression in white blood cells in vitro, and with severe disease and death, while high HO-1 levels were associated with severe disease. Neutrophils were the main HO-1-expressing cells in peripheral blood, and HMOX1 mRNA expression was upregulated by heme-moieties of lysed erythrocytes. We provide mechanistic evidence that induction of HMOX1 expression in neutrophils potentiates the respiratory burst, and propose this may be part of the causal pathway explaining the association between short (GT)(n) repeats and increased disease severity in malaria and other critical illnesses. Our findings suggest a genetic predisposition to higher levels of HO-1 is associated with severe illness, and enhances the neutrophil burst leading to oxidative damage of endothelial cells. These add important information to the discussion about possible therapeutic manipulation of HO-1 in critically ill patients
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Magnetic structure of RCuIn R Nd, Tb, Ho, Er
No full textMagnetic and neutron diffraction measurements of RCuIn (R = Nd, Tb, Ho, Er) are reported. The compounds crystallize in the hexagonal ZrNiAl-type structure. The ZrNiAl lattice originates from a distortion of a kagomélattice. The studied compounds are antiferromagnets with the Néel temperature equal to 4.9 K for R = Nd, 14.5 K for R = Tb, 4.5 K for R = Ho and 3.5 K for R = Er. The magnetic ordering is described by the propagation vectorwe k = (1/2, 1/2, ) with equal to 0.161(6) for R = Nd, 0.2213(5) for R = Tb, 0.2510(3) for R = Ho and 0 for R = Er. The magnetic structure is noncollinear with magnetic moments in the basal plane for R = Nd, Tb and Ho and collinear with magnetic moments parallel to the c-axis for R = Er. The observed magnetic ordering results from the competition between exchange interactions of the Ruderman-Kittel-Kasuya-Yosida type, the geometrical frustration of the rare-earth magnetic moments and the influence of the crystal electric field. The latter affects the direction of magnetic moments and is responsible for the magnetic crystalline anisotropy
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