University of Cagliari

About: University of Cagliari is a education organization based out in Cagliari, Italy. It is known for research contribution in the topics: Population & Dopamine. The organization has 11029 authors who have published 29046 publications receiving 771023 citations. The organization is also known as: Università degli Studi di Cagliari & Universita degli Studi di Cagliari.

Dissection of the HLA association with multiple sclerosis in the founder isolated population of Sardinia

Abstract: Several studies have indicated that multiple sclerosis (MS) is associated and linked to the major histocompatibility complex (MHC)/human leukocyte antigen (HLA) region of chromosome 6p21.3, but the exact location and nature of the primarily associated locus within the HLA complex is still controversial and largely presumptive. By linkage disequilibrium mapping, we have systematically investigated this chromosome region in the founder population of Sardinia to determine the relative associations of the various loci with MS. An overall 11.4 Mb region, which encompasses the whole HLA complex, was scanned with 19 microsatellite markers and with single nucleotide polymorphisms within 12 functional candidate genes and assessed for MS association using the extended transmission disequilibrium test (ETDT). A peak of association represented by the three adjacent DRB1, -DQA1 and -DQB1 loci was detected in the class II region. Two additional less significant areas of association were detected, respectively, in the centromeric side of the class II region at the DPB1 locus and, telomeric of the classically defined class I loci, at the D6S1683 microsatellite. Conditional ETDT analysis indicated that these regions of association could be independent of each other. Within the main peak of association, DRB1 and DQB1 contribute to the disease association independently of each other whereas DQA1 had no detectable primary genetic effects. We evaluated the haplotype distribution at the region showing the strongest association and found five DQB1-DRB1 haplotypes positively associated with MS in Sardinia. These consistently included all the haplotypes previously found associated with MS in the various human populations, thus supporting a primary effect of the products of these loci in MS. Overall these results are consistent with a multilocus model of the MHC encoded susceptibility to MS.

Optical determination of Shockley-Read-Hall and interface recombination currents in hybrid perovskites.

Abstract: Metal-halide perovskite solar cells rival the best inorganic solar cells in power conversion efficiency, providing the outlook for efficient, cheap devices. In order for the technology to mature and approach the ideal Shockley-Queissier efficiency, experimental tools are needed to diagnose what processes limit performances, beyond simply measuring electrical characteristics often affected by parasitic effects and difficult to interpret. Here we study the microscopic origin of recombination currents causing photoconversion losses with an all-optical technique, measuring the electron-hole free energy as a function of the exciting light intensity. Our method allows assessing the ideality factor and breaks down the electron-hole recombination current into bulk defect and interface contributions, providing an estimate of the limit photoconversion efficiency, without any real charge current flowing through the device. We identify Shockley-Read-Hall recombination as the main decay process in insulated perovskite layers and quantify the additional performance degradation due to interface recombination in heterojunctions.