55 research outputs found
Spin-orbit coupling suppression and singlet-state blocking of spin-triplet Cooper pairs
An inhomogeneous magnetic exchange field at a superconductor/ferromagnet interface converts spin-singlet Cooper pairs to a spin-polarized triplet state. Although the decay envelope of triplet pairs within ferromagnetic materials is well studied, little is known about their decay in nonmagnetic metals and superconductors and, in particular, in the presence of spin-orbit coupling (SOC). Here, we investigate devices in which singlet and triplet supercurrents propagate into the s-wave superconductor Nb. In the normal state of Nb, triplet supercurrents decay over a distance of 5 nm, which is an order of magnitude smaller than the decay of spin-singlet pairs due to the SOC. In the superconducting state of Nb, triplet supercurrents are not able to couple with the singlet wave function and are thus blocked by the absence of available equilibrium states in the singlet gap. The results offer insight into the dynamics between s-wave singlet and s-wave triplet states
Distinct genetic architectures and environmental factors associate with host response to the γ2-herpesvirus infections
Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein-Barr Virus (EBV) establish life-long infections and are associated with malignancies. Striking geographic variation in incidence and the fact that virus alone is insufficient to cause disease, suggests other co-factors are involved. Here we present epidemiological analysis and genome-wide association study (GWAS) in 4365 individuals from an African population cohort, to assess the influence of host genetic and non-genetic factors on virus antibody responses. EBV/KSHV co-infection (OR = 5.71(1.58–7.12)), HIV positivity (OR = 2.22(1.32–3.73)) and living in a more rural area (OR = 1.38(1.01–1.89)) are strongly associated with immunogenicity. GWAS reveals associations with KSHV antibody response in the HLA-B/C region (p = 6.64 × 10−09). For EBV, associations are identified for VCA (rs71542439, p = 1.15 × 10−12). Human leucocyte antigen (HLA) and trans-ancestry fine-mapping substantiate that distinct variants in HLA-DQA1 (p = 5.24 × 10−44) are driving associations for EBNA-1 in Africa. This study highlights complex interactions between KSHV and EBV, in addition to distinct genetic architectures resulting in important differences in pathogenesis and transmission
Whole-genome association study of antibody response to Epstein-Barr virus in an African population: a pilot.
Epstein Barr virus (EBV) infects 95% of the global population and is associated with up to 2% of cancers globally. Immunoglobulin G (IgG) antibody levels to EBV have been shown to be heritable and associated with developing malignancies. We, therefore, performed a pilot genome-wide association analysis of anti-EBV IgG traits in an African population, using a combined approach including array genotyping, whole-genome sequencing and imputation to a panel with African sequence data. In 1562 Ugandans, we identify a variant in human leukocyte antigen (HLA)-DQA1, rs9272371 (p = 2.6 × 10-17) associated with anti-EBV nuclear antigen-1 responses. Trans-ancestry meta-analysis and fine-mapping with European-ancestry individuals suggest the presence of distinct HLA class II variants driving associations in Uganda. In addition, we identify four putative, novel, very rare African-specific loci with preliminary evidence for association with anti-viral capsid antigen IgG responses which will require replication for validation. These findings reinforce the need for the expansion of such studies in African populations with relevant datasets to capture genetic diversity.This GPC is jointly funded by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement. Further funding was obtained from the Wellcome Trust (WT098051 and WT090132), the UK Medical Research Council and with federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E
Quantification of the intestinal peptide-containing innervation: length density of nerve fibers and total length of nerve supply to the single villus/crypt unit.
The application of a morphometric method to the quantification of
peptide-containing nerves in the gut is described. It allows a simple estimation
of the nerve fiber supply per unit volume of tissue (length density) and the
calculation of the total nerve fiber supply per unit of intestinal mucosa
(villus/crypt unit)
Risk factors of acute pancreatitis after endoscopic retrograde cholangiopancreatography (E.R.C.P.) and endoscopic papillotomy (E.P.T.)
L'élévation du taux d'amylase sérique après C.P.R.E. et S.E. a été étudiée afin de déterminer les circonstances d'un accroissement du risque de pancréatite aiguë après manipulation endoscopique. Ce risque est significativement supérieur chez les patients à taux d'amylase sérique basal élevé, après douleur à l'injection du produit de contraste, opacification dense des canaux pancréatiques, et retard d'évacuation du produit de contraste sur pancréatogrammes normaux ou révélateurs d'altérations mineures. L'opacification du canal pancréatique principal lors de la sphinctérotomie endoscopique expose un risque identique à celui de la C.P.R.E., si la section est effectuée avec cathéter en place dans la voie biliaire principale (V.B.P.)
Sequence of the Bacillus stearothermophilus gene encoding aspartokinase II
The complete nucleotide sequence of the gene encoding aspartokinase (Ask) II from thermophilic Bacillus stearothermophilus has been determined. Degenerate oligodeoxyribonucleotides primed the amplification of a 932-bp gene. This sequence was successively used for constructing new primers applied in inverse polymerase chain reaction using, as template, self-ligating DNA fragments. The deduced amino-acid sequence is 68.7% identical with the sequence of the Bacillus sp. strain MGA3 Ask II
- …