Polariton propagation in weak confinement quantum wells

Exciton-polariton propagation in a quantum well, under centre-of-mass quantization, is computed by a variational self-consistent microscopic theory. The Wannier exciton envelope functions basis set is given by the simple analytical model of ref. [1], based on pure states of the centre-of-mass wave vector, free from fitting parameters and "ad hoc" (the so called additional boundary conditions-ABCs) assumptions. In the present paper, the former analytical model is implemented in order to reproduce the centre-of-mass quantization in a large range of quantum well thicknesses (5a_B < L < inf.). The role of the dynamical transition layer at the well/barrier interfaces is discussed at variance of the classical Pekar's dead-layer and ABCs. The Wannier exciton eigenstates are computed, and compared with various theoretical models with different degrees of accuracy. Exciton-polariton transmission spectra in large quantum wells (L>> a_B) are computed and compared with experimental results of Schneider et al.\cite{Schneider} in high quality GaAs samples. The sound agreement between theory and experiment allows to unambiguously assign the exciton-polariton dips of the transmission spectrum to the pure states of the Wannier exciton center-of-mass quantization.Comment: 15 pages, 15 figures; will appear in Phys.Rev.

Consensus protocol for EEG and amplitude-integrated EEG assessment and monitoring in neonates

The aim of this work is to establish inclusive guidelines on electroencephalography (EEG) applicable to all neonatal intensive care units (NICUs). Guidelines on ideal EEG monitoring for neonates are available, but there are significant barriers to their implementation in many centres around the world. These include barriers due to limited resources regarding the availability of equipment and technical and interpretive round-the-clock personnel. On the other hand, despite its limitations, amplitude-integrated EEG (aEEG) (previously called Cerebral Function Monitor [CFM]) is a common alternative used in NICUs. The Italian Neonatal Seizure Collaborative Network (INNESCO), working with all national scientific societies interested in the field of neonatal clinical neurophysiology, performed a systematic literature review and promoted interdisciplinary discussions among experts (neonatologists, paediatric neurologists, neurophysiologists, technicians) between 2017 and 2020 with the aim of elaborating shared recommendations. A consensus statement on videoEEG (vEEG) and aEEG for the principal neonatal indications was established. The authors propose a flexible frame of recommendations based on the complementary use of vEEG and aEEG applicable to the various neonatal units with different levels of complexity according to local resources and specific patient features. Suggestions for promoting cooperation between neonatologists, paediatric neurologists, and neurophysiologists, organisational restructuring, and teleneurophysiology implementation are provided

Novel WT1 exon 9 mutation (D396Y) in a patient with early onset Denys Drash syndrome

We identified a novel mutation (867delA) in the glucose-6-phosphatase gene of two siblings with glycogen storage disease type Ia. Although both siblings share the same mutations, their phenotype regarding adult height and hepatomegaly differs. In glycogen storage disease type Ia, substantial heterogeneity in phenotype is observed. Till so far, no evidence for a clear genotype-phenotype correlation has been found. (C) 2000 Wiley-Liss, Inc

Homozygous c.649dupC mutation in PRRT2 worsens the BFIS/PKD phenotype with mental retardation, episodic ataxia, and absences

Heterozygous mutations of PRRT2, which encodes proline-rich transmembrane protein 2, are associated with heterogeneous phenotypes including benign familial infantile seizures (BFIS), or familial paroxysmal kinesigenic dystonia (PKD). We report a consanguineous Italian family with BFIS/PKD phenotype that contained 14 living members with 6 affected individuals (four men, ranging in age from 6-44 years). We identified the reported c.649dupC (p.Arg217ProfsX8) mutation of PRRT2 gene that cosegregated with the disease and was not observed in 100 controls of matched ancestry. Four patients with BFIS phenotype were heterozygous for this mutation, including the consanguineous parents of the two affected brothers with more severe phenotypes of BFIS/PKD-mental retardation, episodic ataxia, and absences-who were the only individuals to carry a homozygous c.649dupC mutation. This family provides strong evidence that homozygous PRRT2 mutations give rise to more severe clinical disease of mental retardation, episodic ataxia, and absences, and, thus, enlarges the clinical spectrum related to PRRT2 mutations. Moreover, it suggests an additive effect of double dose of the genetic mutation and underscores the complexity of the phenotypic consequences of mutations in this gene. \ua9 2012 International League Against Epilepsy

Ketogenic diet in Lafora disease: a long term follow-up pilot study

PURPOSE: Lafora body disease (LBD) is severe and rapidly worsening progressive myoclonus epilepsy (PME), not treatable with specific therapy. In LBD patients, typical polyglucosan accumulations result from alterations of proteins involved in the regulation of glycogen metabolism. Thus, a ketogenic regimen might reasonably be expected to counteract the disease progression. We set out to assess the feasibility and tolerability of a long-term ketogenic diet (KD) in LBD patients and to make a preliminary evaluation of its effect on the disease course. METHODS: We treated five LBD patients with KD and evaluated the changes in the clinical, neuropsychological and neurophysiological findings over 10-30 months. RESULTS: The KD was well tolerated in all the patients for the first 16 months. Nutritional measures and laboratory findings remained substantially stable. The disease progressed in all the patients, reaching an advanced stage in one. Electrophysiological findings indicated the presence of increased cortical excitability in four patients, paralleling the worsening of the myoclonus. CONCLUSION: KD was unable to stop the disease progression. However, given the considerable heterogeneity of the natural history of LBD, we cannot exclude the possibility that KD has the potential to slow down the disease progression. The application of this nutritional approach should be further evaluated in larger case series