1,582 research outputs found

    Majorana corner modes and flat-band Majorana edge modes in superconductor/topological-insulator/superconductor junctions

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    Recently, superconductors with higher-order topology have stimulated extensive attention and research interest. Higher-order topological superconductors exhibit unconventional bulk-boundary correspondence, thus allow exotic lower-dimensional boundary modes, such as Majorana corner and hinge modes. However, higher-order topological superconductivity has yet to be found in naturally occurring materials. In this work, we investigate higher-order topology in a two-dimensional Josephson junction comprised of two ss-wave superconductors separated by a topological insulator thin film. We found that zero-energy Majorana corner modes, a boundary fingerprint of higher-order topological superconductivity, can be achieved by applying magnetic field. When an in-plane Zeeman field is applied to the system, two corner states appear in the superconducting junction. Furthermore, we also discover a two dimensional nodal superconducting phase which supports flat-band Majorana edge modes connecting the bulk nodes. Importantly, we demonstrate that zero-energy Majorana corner modes are stable when increasing the thickness of topological insulator thin film.Comment: 9 pages, 4 figure

    Comparative Cytogenetics Analysis of Chlamys farreri, Patinopecten yessoensis, and Argopecten irradians with C0t-1 DNA by Fluorescence In Situ Hybridization

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    The chromosomes of Chlamys farreri, Patinopecten yessoensis, and Argopecten irradians were studied by FISH using C. farreri C0t-1 DNA probes. The results showed that C0t-1 DNA signals spread on all chromosomes in the three scallops, whereas signal density and intensity were different strikingly. Clustering brighter signals presented in the centromeric and telomeric regions of most C. farreri chromosomes, and in the centromeric or pericentromeric regions of several P. yessoensis chromosomes. Comparative analysis of the mapping indicated a relatively higher homology in the repetitive DNA sequences of the genome between C. farreri and P. yessoensis than that between C. farreri and A. irradians. In addition, FISH showed that the distribution of C0t-1 DNA clustering signals in C. farreri displayed completely similar signal bands between homologous chromosomes. Based on the C0t-1 DNA fluorescent bands, a more exact karyotype of C. farreri has been obtained. In this study, the comparative analysis based on C0t-1 DNA provides a new insight into the chromosomal reconstructions during the evolution process, and it is helpful for understanding an important source of genomic diversity, species relationships, and genome evolution

    Empirical modeling of the stellar spectrum of galaxies

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    An empirical method of modeling the stellar spectrum of galaxies is proposed, based on two successive applications of Principal Component Analysis (PCA). PCA is first applied to the newly available stellar library STELIB, supplemented by the J, H and Ks_{s} magnitudes taken mainly from the 2 Micron All Sky Survey (2MASS). Next the resultant eigen-spectra are used to fit the observed spectra of a sample of 1016 galaxies selected from the Sloan Digital Sky Survey Data Release One (SDSS DR1). PCA is again applied, to the fitted spectra to construct the eigen-spectra of galaxies with zero velocity dispersion. The first 9 galactic eigen-spectra so obtained are then used to model the stellar spectrum of the galaxies in SDSS DR1, and synchronously to estimate the stellar velocity dispersion, the spectral type, the near-infrared SED, and the average reddening. Extensive tests show that the spectra of different type galaxies can be modeled quite accurately using these eigen-spectra. The method can yield stellar velocity dispersion with accuracies better than 10%, for the spectra of typical S/N ratios in SDSS DR1.Comment: 34 pages with 18 figures, submitted to A

    Interictal magnetoencephalographic findings related with surgical outcomes in lesional and nonlesional neocortical epilepsy

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    Purpose: To investigate whether interictal magnetoencephalography (MEG) concordant with other techniques can predict surgical outcome in patients with lesional and nonlesional refractory neocortical epilepsy (NE). Methods: 23 Patients with lesional NE and 20 patients with nonlesional NE were studied. MEG was recorded for all patients with a 275 channel whole-head system. Synthetic aperture magnetometry (SAM) with excess kurtosis (g2) and conventional Equivalent Current Dipole (ECD) were used for MEG data analysis. 27 Patients underwent long-term extraoperative intracranial video electroencephalography (iVEEG) monitoring. Surgical outcomes were assessed based on more than 1-year of post-surgical follow-up using Engel classification system. Results: As we expected, both favorable outcomes (Engel class I or II) and seizure freedom outcomes (Engel class IA) were higher for the concordance condition (MEG findings are concordant with MRI or iVEEG findings) versus the discordance condition. Also the seizure free rate was significantly higher (x2 = 5.24, P \u3c 0.05) for the patients with lesional NE than for the patients with nonlesional NE. In 30% of the patients with nonlesional NE, the MEG findings proved to be valuable for intracranial electrode implantation. Conclusions: This study demonstrates that a favorable post-surgical outcome can be obtained in most patients with concordant MEG and MRI results even without extraoperative iVEEG monitoring, which indicates that the concordance among different modalities could indicate a likelihood of better postsurgical outcomes. However, extraoperative iVEEG monitoring remains prerequisite to the patients with discordant MEG and MRI findings. For nonlesional cases, our results showed that MEG could provide critical information in the placement of intracranial electrodes

    Polymorphism of rs1044925 in the acyl-CoA:cholesterol acyltransferase-1 gene and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

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    <p>Abstract</p> <p>Background</p> <p>The association of rs1044925 polymorphism in the acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) gene and serum lipid profiles is not well known in different ethnic groups. Bai Ku Yao is a special subgroup of the Yao minority in China. The present study was carried out to clarify the association of rs1044925 polymorphism in the ACAT-1 gene and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.</p> <p>Methods</p> <p>A total of 626 subjects of Bai Ku Yao and 624 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of rs1044925 polymorphism in the ACAT-1 gene was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.</p> <p>Results</p> <p>The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (<it>P </it>< 0.01 for all). The frequency of A and C alleles was 79.0% and 21.0% in Bai Ku Yao, and 87.3% and 12.7% in Han (<it>P </it>< 0.001); respectively. The frequency of AA, AC and CC genotypes was 63.2%, 31.4% and 5.2% in Bai Ku Yao, and 75.6%, 23.2% and 1.1% in Han (<it>P </it>< 0.001); respectively. The levels of TC, LDL-C and ApoB in Bai Ku Yao but not in Han were different between the AA and AC/CC genotypes in females but not in males (<it>P </it>< 0.05 for all). The C allele carriers had lower serum TC, LDL-C and ApoB levels as compared with the C allele noncarriers. The levels of TC, LDL-C and ApoB in Bai Ku Yao but not in Han were correlated with genotypes in females but not in males (<it>P </it>< 0.05 for all). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, and blood pressure in both ethnic groups (<it>P </it>< 0.05-0.001).</p> <p>Conclusions</p> <p>These results suggest that the polymorphism of rs1044925 in the ACAT-1 gene is mainly associated with female serum TC, LDL-C and ApoB levels in the Bai Ku Yao population. The C allele carriers had lower serum TC, LDL-C and ApoB levels than the C allele noncarriers.</p

    Sex-specific association of ACAT-1 rs1044925 SNP and serum lipid levels in the hypercholesterolemic subjects

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    <p>Abstract</p> <p>Background</p> <p>Acyl-CoA:cholesterol acyltransferase (ACAT) is a key enzyme in cellular cholesterol homeostasis and in atherosclerosis. The cellular cholesterol efflux correlated with serum high-density lipoprotein cholesterol (HDL-C) concentrations has shown to be impaired in hyperlipidemic mice. The present study was carried out to clarify the association of ACAT-1 rs1044925 single nucleotide polymorphism (SNP) and serum lipid levels in the hyperlipidemic subjects.</p> <p>Methods</p> <p>A total of 821 unrelated subjects (hyperlipidemia, 476; normolipidemia, 345) aged 15-80 were included in the study. Genotyping of the ACAT-1 rs1044925 SNP was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.</p> <p>Results</p> <p>There was no significant difference in the genotypic and allelic frequencies of ACAT-1 rs1044925 SNP between the normolipidemic and hyperlipidemic subjects. The levels of total cholesterol (TC), HDL-C and apolipoprotein (Apo) AI in hyperlipidemic subjects were different between the AA and AC/CC genotypes in male but not in female (<it>P </it>< 0.05-0.01), the C allele carriers had higher serum TC, HDL-C and ApoAI levels than the C allele noncarriers. The association of genotypes and serum HDL-C and ApoAI levels in hyperlipidemia was found mainly in the male subjects with hypercholesterolemia but not in those with hypertriglyceridemia. There were no significant differences in serum lipid levels between the AA and AC/CC genotypes in the normolipidemic subjects.</p> <p>Conclusions</p> <p>The present study shows that the C allele carriers of ACAT-1 rs1044925 SNP in male hyperlipidemic subjects had higher serum TC, HDL-C and ApoAI levels than the C allele noncarriers. There is a sex (male)-specific association of ACAT-1 rs1044925 SNP and serum HDL-C and ApoAI levels in the hypercholesterolemic subjects.</p

    Estradiol Promotes M1-like Macrophage Activation through Cadherin-11 To Aggravate Temporomandibular Joint Inflammation in Rats

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    Macrophages play a major role in joint inflammation. Estrogen is involved in rheumatoid arthritis and temporomandibular disorders. However, the underlying mechanism is still unclear. This study was done to verify and test how estrogen affects M1/M2-like macrophage polarization and then contributes to joint inflammation. Female rats were ovariectomized and treated with increasing doses of 17Ī²-estradiol for 10 d and then intra-articularly injected with CFA to induce temporomandibular joint (TMJ) inflammation. The polarization of macrophages and expression of cadherin-11 was evaluated at 24 h after the induction of TMJ inflammation and after blocking cadherin-11 or estrogen receptors. NR8383 macrophages were treated with estradiol and TNF-Ī±, with or without blocking cadherin-11 or estrogen receptors, to evaluate the expression of the M1/M2-like macrophageassociated genes. We found that estradiol increased the infiltration of macrophages with a proinflammatory M1-like predominant profile in the synovium of inflamed TMJ. In addition, estradiol dose-dependently upregulated the expressions of the M1-associated proinflammatory factor inducible NO synthase (iNOS) but repressed the expressions of the M2-associated genes IL-10 and arginase in NR8383 macrophages. Furthermore, estradiol mainly promoted cadherin-11 expression in M1-like macrophages of inflamed TMJ. By contrast, blockage of cadherin-11 concurrently reversed estradiol-potentiated M1-like macrophage activation and TMJ inflammation, as well as reversed TNF-Ī±-induced induction of inducible NO synthase and NO in NR8383 macrophages. The blocking of estrogen receptors reversed estradiol-potentiated M1-like macrophage activation and cadherin-11 expression. These results suggested that estradiol could promote M1-like macrophage activation through cadherin-11 to aggravate the acute inflammation of TMJs. Copyright Ā© 2015 by The American Association of Immunologists, Inc

    The proprotein convertase subtilisin/kexin type 9 gene E670G polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

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    <p>Abstract</p> <p>Background</p> <p>Proprotein convertase subtilisin-like kexin type 9 (PCSK9) plays a key role in regulating plasma low-density lipoprotein cholesterol (LDL-C) levels. However, the association of E670G (rs505151) polymorphism in the PCSK9 gene and serum lipid levels is inconsistent in several previous studies. The present study was undertaken to detect the association of PCSK9 E670G polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.</p> <p>Methods</p> <p>A total of 649 subjects of Bai Ku Yao and 646 participants of Han were randomly selected from our previous samples. Genotypes of the PCSK9 E670G polymorphism were determined via polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.</p> <p>Results</p> <p>Serum levels of total cholesterol, high-density lipoprotein cholesterol (HDL-C), LDL-C, and apolipoprotein (Apo) AI were lower in Bai Ku Yao than in Han (<it>P </it>< 0.01 for all). The frequency of G allele was 2.00% in Bai Ku Yao and 4.80% in Han (<it>P </it>< 0.01). There was significant difference in the genotypic and allelic frequencies between Bai Ku Yao and Han (<it>P </it>< 0.01); between normal LDL-C (ā‰¤ 3.20 mmol/L) and high LDL-C subgroups (> 3.20 mmol/L, <it>P </it>< 0.01) in Bai Ku Yao; and between normal HDL-C (ā‰„ 0.91 mmol/L) and low HDL-C (< 0.91 mmol/L, <it>P </it>< 0.05), between normal ApoAI (ā‰„ 1.00 g/L) and low ApoAI (< 1.00 g/L, <it>P </it>< 0.05), or between normal ApoAI/ApoB ratio (ā‰„ 1.00) and low ApoAI/ApoB ratio (< 1.00, <it>P </it>< 0.01) subgroups in Han. The G allele carriers in Han had higher serum HDL-C levels and the ratio of ApoAI to ApoB than the G allele noncarriers. The G allele carriers in Han had higher serum HDL-C and ApoAI levels than the G allele noncarriers in males (<it>P </it>< 0.05 for each), whereas the G allele carriers had lower serum ApoB levels and higher the ratio of ApoAI to ApoB than the G allele noncarriers in females (<it>P </it>< 0.05 for all). Serum HDL-C and ApoAI levels in Han were correlated with genotypes (<it>P </it>< 0.05) in males, and serum ApoB levels and the ratio of ApoAI to ApoB were associated with genotypes (<it>P </it>< 0.05) in females.</p> <p>Conclusions</p> <p>The PCSK9 E670G polymorphism is mainly associated with some serum lipid parameters in the Han population. The G allele carriers had higher serum HDL-C and ApoAI levels in males, and lower serum ApoB levels and higher the ApoAI/ApoB ratio in females than the G allele noncarriers.</p
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