4 research outputs found
Recommended from our members
Reactive plasma cleaning and restoration of transition metal dichalcogenide monolayers
The cleaning of two-dimensional (2D) materials is an essential step in the fabrication of future devices, leveraging their unique physical, optical, and chemical properties. Part of these emerging 2D materials are transition metal dichalcogenides (TMDs). So far there is limited understanding of the cleaning of “monolayer” TMD materials. In this study, we report on the use of downstream H2 plasma to clean the surface of monolayer WS2 grown by MOCVD. We demonstrate that high-temperature processing is essential, allowing to maximize the removal rate of polymers and to mitigate damage caused to the WS2 in the form of sulfur vacancies. We show that low temperature in situ carbonyl sulfide (OCS) soak is an efficient way to resulfurize the material, besides high-temperature H2S annealing. The cleaning processes and mechanisms elucidated in this work are tested on back-gated field-effect transistors, confirming that transport properties of WS2 devices can be maintained by the combination of H2 plasma cleaning and OCS restoration. The low-damage plasma cleaning based on H2 and OCS is very reproducible, fast (completed in a few minutes) and uses a 300 mm industrial plasma etch system qualified for standard semiconductor pilot production. This process is, therefore, expected to enable the industrial scale-up of 2D-based devices, co-integrated with silicon technology
STXBP1 encephalopathy: A neurodevelopmental disorder including epilepsy
OBJECTIVE
To give a comprehensive overview of the phenotypic and genetic spectrum of STXBP1 encephalopathy (STXBP1-E) by systematically reviewing newly diagnosed and previously reported patients.
METHODS
We recruited newly diagnosed patients with STXBP1 mutations through an international network of clinicians and geneticists. Furthermore, we performed a systematic literature search to review the phenotypes of all previously reported patients.
RESULTS
We describe the phenotypic features of 147 patients with STXBP1-E including 45 previously unreported patients with 33 novel STXBP1 mutations. All patients have intellectual disability (ID), which is mostly severe to profound (88%). Ninety-five percent of patients have epilepsy. While one-third of patients presented with Ohtahara syndrome (21%) or West syndrome (9.5%), the majority has a nonsyndromic early-onset epilepsy and encephalopathy (53%) with epileptic spasms or tonic seizures as main seizure type. We found no correlation between severity of seizures and severity of ID or between mutation type and seizure characteristics or cognitive outcome. Neurologic comorbidities including autistic features and movement disorders are frequent. We also report 2 previously unreported adult patients with prominent extrapyramidal features.
CONCLUSION
De novo STXBP1 mutations are among the most frequent causes of epilepsy and encephalopathy. Most patients have severe to profound ID with little correlation among seizure onset, seizure severity, and the degree of ID. Accordingly, we hypothesize that seizure severity and ID present 2 independent dimensions of the STXBP1-E phenotype. STXBP1-E may be conceptualized as a complex neurodevelopmental disorder rather than a primary epileptic encephalopathy
Faustzahlen für den Ökologischen Landbau
Die Faustzahlen bieten einen kompakten Überblick über den Ökologischen Landbau. Ob pflanzliche oder tierische Erzeugung, Lagerung und Vermarktung, Betriebsfüh-rung oder Biodiversität – die Faustzahlen liefern auf fast alle Fragen der Praxis eine Antwort.
Dieses Buch gewährt Einblick in die besonderen Bedingungen des Ökolandbaus, vor allem in seine Kosten- und Leistungsstrukturen, aber auch in seine Möglichkeiten mit Herausforderungen umzugehen, wie z. B. Nährstoffversorgung oder Unkrautdruck.
Ob es um Überschlagsrechnungen oder Vorplanungen geht, dieses Nachschlage-werk schließt Lücken, wenn eigene Daten und Erfahrungen fehlen. Die Inhalte sind in Tabellen strukturiert, in Grafiken veranschaulicht und in kurzen Texten erläutert. Die „Faustzahlen für den Ökologischen Landbau“ sind unentbehrlich für alle, die es genau wissen wollen.
Die 760-seitige Schrift ist als Printversion für 30 € und als digitale Version für 27 € beim Kuratorium für Technik und Bauwesen in der Landwirtschaft (KTBL) e.V. er-hältlich. In der digitalen Version lassen sich Zahlen und Fakten online recherchieren und Verlinkungen direkt aufrufen