71 research outputs found
The role of the laser pulse duration in infrared matrix-assisted laser desorption/ionization mass spectrometry
Biallelic ADAM22 pathogenic variants cause progressive encephalopathy and infantile-onset refractory epilepsy
Pathogenic variants in A Disintegrin And Metalloproteinase (ADAM) 22, the postsynaptic cell membrane receptor for the glycoprotein leucine-rich repeat glioma-inactivated protein 1 (LGI1), have been recently associated with recessive developmental and epileptic encephalopathy. However, so far, only two affected individuals have been described and many features of this disorder are unknown. We refine the phenotype and report 19 additional individuals harbouring compound heterozygous or homozygous inactivating ADAM22 variants, of whom 18 had clinical data available. Additionally, we provide follow-up data from two previously reported cases. All affected individuals exhibited infantile-onset, treatment-resistant epilepsy. Additional clinical features included moderate to profound global developmental delay/intellectual disability (20/20), hypotonia (12/20) and delayed motor development (19/20). Brain MRI findings included cerebral atrophy (13/20), supported by post-mortem histological examination in patient-derived brain tissue, cerebellar vermis atrophy (5/20), and callosal hypoplasia (4/20). Functional studies in transfected cell lines confirmed the deleteriousness of all identified variants and indicated at least three distinct pathological mechanisms: (i) defective cell membrane expression; (ii) impaired LGI1-binding; and/or (iii) impaired interaction with the postsynaptic density protein PSD-95. We reveal novel clinical and molecular hallmarks of ADAM22 deficiency and provide knowledge that might inform clinical management and early diagnostics. Van der Knoop et al. describe the clinical features of 21 individuals with biallelic pathogenic variants in ADAM22 and confirm the deleteriousness of the variants with functional studies. Clinical hallmarks of this rare disorder comprise progressive encephalopathy and infantile-onset refractory epilepsy.Peer reviewe
Biallelic ADAM22 pathogenic variants cause progressive encephalopathy and infantile-onset refractory epilepsy
Pathogenic variants in A Disintegrin And Metalloproteinase (ADAM) 22, the postsynaptic cell membrane receptor for the glycoprotein leucine-rich repeat glioma-inactivated protein 1 (LGI1), have been recently associated with recessive developmental and epileptic encephalopathy. However, so far, only two affected individuals have been described and many features of this disorder are unknown. We refine the phenotype and report 19 additional individuals harboring compound heterozygous or homozygous inactivating ADAM22 variants, of whom 18 had clinical data available. Additionally, we provide follow-up data from two previously reported cases. All affected individuals exhibited infantile-onset, treatment-resistant epilepsy. Additional clinical features included moderate to profound global developmental delay/intellectual disability (20/20), hypotonia (12/20), delayed motor development (19/20). Brain MRI findings included cerebral atrophy (13/20), supported by post-mortem histological examination in patient-derived brain tissue, cerebellar vermis atrophy (5/20), and callosal hypoplasia (4/20). Functional studies in transfected cell lines confirmed the deleteriousness of all identified variants and indicated at least three distinct pathological mechanisms: defective cell membrane expression (1), impaired LGI1-binding (2), and/or impaired interaction with the postsynaptic density protein PSD-95 (3). We reveal novel clinical and molecular hallmarks of ADAM22 deficiency and provide knowledge that might inform clinical management and early diagnostics
Semiconductor Spintronics
Spintronics refers commonly to phenomena in which the spin of electrons in a
solid state environment plays the determining role. In a more narrow sense
spintronics is an emerging research field of electronics: spintronics devices
are based on a spin control of electronics, or on an electrical and optical
control of spin or magnetism. This review presents selected themes of
semiconductor spintronics, introducing important concepts in spin transport,
spin injection, Silsbee-Johnson spin-charge coupling, and spindependent
tunneling, as well as spin relaxation and spin dynamics. The most fundamental
spin-dependent nteraction in nonmagnetic semiconductors is spin-orbit coupling.
Depending on the crystal symmetries of the material, as well as on the
structural properties of semiconductor based heterostructures, the spin-orbit
coupling takes on different functional forms, giving a nice playground of
effective spin-orbit Hamiltonians. The effective Hamiltonians for the most
relevant classes of materials and heterostructures are derived here from
realistic electronic band structure descriptions. Most semiconductor device
systems are still theoretical concepts, waiting for experimental
demonstrations. A review of selected proposed, and a few demonstrated devices
is presented, with detailed description of two important classes: magnetic
resonant tunnel structures and bipolar magnetic diodes and transistors. In most
cases the presentation is of tutorial style, introducing the essential
theoretical formalism at an accessible level, with case-study-like
illustrations of actual experimental results, as well as with brief reviews of
relevant recent achievements in the field.Comment: tutorial review; 342 pages, 132 figure
Intact and top-down characterization of biomolecules and direct analysis using infrared matrix-assisted laser desorption electrospray ionization coupled to FT-ICR mass spectrometry
Estimation of the proton affinity values of fifteen matrix-assisted laser desorption/ionization matrices under electrospray ionization conditions using the kinetic method
Establishment and characterization of C-type RNA virus-producing cell lines from radiation-induced murine osteosarcomas.
Eight cell lines were established from murine osteosarcomas induced in vivo with the radionuclides 224Ra and 227Th. They have been compared by light and electron microscopy, by karyology, and by their growth properties. The morphology, the growth pattern, and the ability to induce tumors in mice indicate that five of them are tumor cell lines. Chromosome studies demonstrated that the five cell lines have marker chromosomes. The other cell lines only showed some criteria generally used to score for transformation of fibroblasts and they may be derived from stromal cells. All cell lines release virus particles in the culture fluid which have the typical properties of RNA tumor viruses. They possess C-type morphology, a density of 1.16--1.18 g/cm3, a 60--70 S RNA, a RNA dependent DNA polymerase and they induce syncytia in rat XC cells. The possible significance of these virus particles in radiation osteosarcomagenesis is discussed
Hydrogen Incorporation and Diffusivity in Plasma-Exposed Bulk ZnO
Hydrogen incorporation depths of \u3e25 μm were obtained in bulk, single-crystal ZnO during exposure to 2H plasmas for 0.5 h at 300 °C, producing an estimated diffusivity of ∼ 8×10−10 cm2/V⋅s at this temperature. The activation energy for diffusion was 0.17±0.12 eV, indicating an interstitial mechanism. Subsequent annealing at 500–600 °C was sufficient to evolve all of the hydrogen out of the ZnO, at least to the sensitivity of secondary ion mass spectrometry (\u3c5×1015 cm−3). The thermal stability of hydrogen retention is slightly greater when the hydrogen is incorporated by direct implantation relative to plasma exposure, due to trapping at residual damage in the former case
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