171 research outputs found

    Interlayer pair tunneling and gap anisotropy in YBa2_2Cu3_3O7βˆ’Ξ΄_{7-\delta}

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    Recent ARPES measurement observed a large abab-axis gap anisotropy, Ξ”(0,Ο€)/Ξ”(Ο€,0)=1.5\Delta(0,\pi)/\Delta(\pi,0)=1.5, in clean YBa2_2Cu3_3O7βˆ’Ξ΄_{7-\delta}. This indicates that some sub-dominant component may exist in the dx2βˆ’y2d_{x^2-y^2}-wave dominant gap. We propose that the interlayer pairing tunneling contribution can be determined through the investigation of the order parameter anisotropy. Their potentially observable features in transport and spin dynamics are also studied.Comment: 4 pages, 3 figure

    UbicaciΓ³n y peso de Micelio de Sclerotinia sclerotiorum para producir infeccion en lechuga (Lactuca sativa)

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    p.85-88El objetivo del presente trabajo es evaluar la distancia crΓ­tica para la inoculaciΓ³n del micelio de Sclerotinia sclerotiorum al cuello de la planta de lechuga (Lactuca sativa) y el peso del mismo para producir infecciΓ³n y caΓ­da de las plΓ‘ntulas en cΓ‘mara de cultivo. La mayor cantidad de plantas caΓ­das se obtuvo con 0,7 y 2,8 grs de inoculo (masa miceliar) ubicado junto al cuello de la planta. Estos resultados pueden ser de utilidad para estudios acerca del control cultural, quΓ­mico o biolΓ³gico de la podredumbre ocasionada por S. sclerotiorum en lechuga

    Evolution of 18F-FDG-PET/CT findings in patients following COVID-19 pneumonia: An Initial Investigation

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    Background: The evolution of pulmonary 18F-FDG uptake is unknown in patients with pneumonia due to SARS-CoV-2 (COVID-19 pneumonia) and in those with persistent respiratory symptoms post-COVID-19 termed Post-COVID-19 Lung-Disease (PCLD). The aim of this study was to assess the temporal evolution of pulmonary 18F-FDG uptake and identify a potential role for the use of 18F-FDG-PET/CT imaging in the management of these patients. Methods: Clinical data and CT imaging of all patients that underwent 18F-FDG-PET/CT imaging at UCLH, Lon-don during the UK pandemic were reviewed to find evidence of active or recovered SARS-CoV-2 infection. Results of PCR tests were used where available. Patients were divided in to acute (early and late) COVID-19 pneumonia, PCLD and asymptomatic recovery. 18F-FDG uptake in the lungs was measured as a target-to-background ratio (SUVmax/SUVmin) TBRlung which was compared to temporal-stage and plasma CRP. Results: There were 50 patients in total (median 61y, range 18-87y, 32-male): 23 incidental acute COVID-19 pneumonia cases identified retrospectively (8 Early, 15 Late), 9 asymptomatic recovered patients, and 18 cases performed for PCLD. In acute COVID-19 patients <3 weeks since disease onset TBRlung was strongly correlated with time since disease onset (rs=0.81, p<0.001)

    Hydrogen and 40Ar/39Ar isotope evidence for multiple and protracted paleofluid flow events within the long‐lived North Anatolian Keirogen (Turkey)

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    We present a new approach to identifying the source and age of paleofluids associated with low‐temperature deformation in the brittle crust, using hydrogen isotopic compositions (Ξ΄D) and 40Ar/39Ar geochronology of authigenic illite in clay gouge‐bearing fault zones. The procedure involves grain‐size separation, polytype modeling, and isotopic analysis, creating a mixing line that is used to extrapolate to Ξ΄D and age of pure authigenic and detrital material. We use this method on samples collected along the surface trace of today's North Anatolian Fault (NAF). Ξ΄D values of the authigenic illite population, obtained by extrapolation, are βˆ’89 ± 3‰, βˆ’90 ± 2‰, and βˆ’97 ± 2‰ (VSMOW) for samples KSL, RES4‐1, and G1G2, respectively. These correspond to Ξ΄D fluid values of βˆ’62‰ to βˆ’85‰ for the temperature range of 125Β°C ± 25Β°, indistinguishable from present‐day precipitation values. Ξ΄D values of the detrital illite population are βˆ’45 ± 13‰, βˆ’60 ± 6‰, and βˆ’64 ± 6‰ for samples KSL, G1G2, and RES4‐1, respectively. Corresponding Ξ΄D fluid values at 300Β°C are βˆ’26‰ to βˆ’45‰ and match values from adjacent metamorphic terranes. Corresponding clay gouge ages are 41.4 ± 3.4 Ma (authigenic) and 95.8 ± 7.7 Ma (detrital) for sample G2 and 24.6 ± 1.6 Ma (authigenic) and 96.5 ± 3.8 Ma (detrital) for sample RES4‐1, demonstrating a long history of meteoric fluid infiltration in the area. We conclude that today's NAF incorporated preexisting, weak clay‐rich rocks that represent earlier mineralizing fluid events. The samples preserve at least three fluid flow pulses since the Eocene and indicate that meteoric fluid has been circulating in the upper crust in the North Anatolian Keirogen since that time.Key Points:Illite preserves the hydrogen isotopic signature and age of paleofluids in the earth's upper crustThree fluid events are pinpointed in the NAKThe NAF exploited zones of preexisting weak clay material during its formationPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/112210/1/ggge20754.pd

    HLA-associated susceptibility to childhood B-cell precursor ALL: definition and role of HLA-DPB1 supertypes

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    Childhood B-cell precursor (BCP) ALL is thought to be caused by a delayed immune response to an unidentified postnatal infection. An association between BCP ALL and HLA class II (DR, DQ, DP) alleles could provide further clues to the identity of the infection, since HLA molecules exhibit allotype-restricted binding of infection-derived antigenic peptides. We clustered >30 HLA-DPB1 alleles into six predicted peptide-binding supertypes (DP1, 2, 3, 4, 6, and 8), based on amino acid di-morphisms at positions 11 (G/L), 69 (E/K), and 84 (G/D) of the DPΞ²1 domain. We found that the DPΞ²11-69-84 supertype GEG (DP2), was 70% more frequent in BCP ALL (n=687; P<10βˆ’4), and 98% more frequent in cases diagnosed between 3 and 6 years (P<10βˆ’4), but not <3 or >6 years, than in controls. Only one of 21 possible DPB1 supergenotypes, GEG/GKG (DP2/DP4) was significantly more frequent in BCP ALL (P=0.00004) than controls. These results suggest that susceptibility to BCP ALL is associated with the DP2 supertype, which is predicted to bind peptides with positively charged, nonpolar aromatic residues at the P4 position, and hydrophobic residues at the P1 and P6 positions. Studies of peptide binding by DP2 alleles could help to identify infection(s) carrying these peptides

    Discovering Cooperative Relationships of Chromatin Modifications in Human T Cells Based on a Proposed Closeness Measure

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    BACKGROUND: Eukaryotic transcription is accompanied by combinatorial chromatin modifications that serve as functional epigenetic markers. Composition of chromatin modifications specifies histone codes that regulate the associated gene. Discovering novel chromatin regulatory relationships are of general interest. METHODOLOGY/PRINCIPAL FINDINGS: Based on the premise that the interaction of chromatin modifications is hypothesized to influence CpG methylation, we present a closeness measure to characterize the regulatory interactions of epigenomic features. The closeness measure is applied to genome-wide CpG methylation and histone modification datasets in human CD4+T cells to select a subset of potential features. To uncover epigenomic and genomic patterns, CpG loci are clustered into nine modules associated with distinct chromatin and genomic signatures based on terms of biological function. We then performed Bayesian network inference to uncover inherent regulatory relationships from the feature selected closeness measure profile and all nine module-specific profiles respectively. The global and module-specific network exhibits topological proximity and modularity. We found that the regulatory patterns of chromatin modifications differ significantly across modules and that distinct patterns are related to specific transcriptional levels and biological function. DNA methylation and genomic features are found to have little regulatory function. The regulatory relationships were partly validated by literature reviews. We also used partial correlation analysis in other cells to verify novel regulatory relationships. CONCLUSIONS/SIGNIFICANCE: The interactions among chromatin modifications and genomic elements characterized by a closeness measure help elucidate cooperative patterns of chromatin modification in transcriptional regulation and help decipher complex histone codes

    Mitochondrial Mutations in Adenoid Cystic Carcinoma of the Salivary Glands

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    Background: The MitoChip v2.0 resequencing array is an array-based technique allowing for accurate and complete sequencing of the mitochondrial genome. No studies have investigated mitochondrial mutation in salivary gland adenoid cystic carcinomas. Methodology: The entire mitochondrial genome of 22 salivary gland adenoid cystic carcinomas (ACC) of salivary glands and matched leukocyte DNA was sequenced to determine the frequency and distribution of mitochondrial mutations in ACC tumors. Principal Findings: Seventeen of 22 ACCs (77%) carried mitochondrial mutations, ranging in number from 1 to 37 mutations. A disproportionate number of mutations occurred in the D-loop. Twelve of 17 tumors (70.6%) carried mutations resulting in amino acid changes of translated proteins. Nine of 17 tumors (52.9%) with a mutation carried an amino acid changing mutation in the nicotinamide adenine dinucleotide dehydrogenase (NADH) complex. Conclusions/Significance: Mitochondrial mutation is frequent in salivary ACCs. The high incidence of amino acid changing mutations implicates alterations in aerobic respiration in ACC carcinogenesis. D-loop mutations are of unclear significance
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