55 research outputs found
Establishment and characterisation of a human carcinoma cell line with acquired resistance to Aplidinâą
Influencing the properties of dysprosium single-molecule magnets with phosphine, phosphide and phosphinidene ligands
Single-molecule magnets are a type of coordination compound that can retain magnetic information at low temperatures. Single-molecule magnets based on lanthanides have accounted for many important advances, including systems with very large energy barriers to reversal of the magnetization, and a di-terbium complex that displays magnetic hysteresis up to 14 K and shows strong coercivity. Ligand design is crucial for the development of new single-molecule magnets: organometallic chemistry presents possibilities for using unconventional ligands, particularly those with soft donor groups. Here we report dysprosium single-molecule magnets with neutral and anionic phosphorus donor ligands, and show that their properties change dramatically when varying the ligand from phosphine to phosphide to phosphinidene. A phosphide-ligated, trimetallic dysprosium single-molecule magnet relaxes via the second-excited Kramersâ doublet, and, when doped into a diamagnetic matrix at the single-ion level, produces a large energy barrier of 256 cm1 and magnetic hysteresis up to 4.4 K
Central nervous system and muscular bundles preserved in a 240 million year old giant bristletail (Archaeognatha: Machilidae)
Among the incomparably diverse group of insects no cases of central nervous system (CNS) preservation have been so far described in compression fossils. A third of the fossil insects collected from a 240-239 million year old (Ma) level at Monte San Giorgio UNESCO World Heritage (SwitzerlandItaly) underwent phosphatization, resulting in the extraordinary preservation of soft tissues. Here we describe Gigamachilis triassicus gen. et sp. nov. (Archaeognatha: Machiloidea: Machilidae) that, with an estimated total length of similar to 80 millimeters, represents the largest apterygote insect ever recorded. The holotype preserves: (i) components of the CNS represented by four abdominal ganglia, optic lobes with neuropils and compound retina;(ii) muscular bundles. Moreover, G. triassicus, possessing morphological features that prompt its assignment to the extant archaeognathan ingroup Machilidae, places the origin of modern lineages to Middle Triassic. Interestingly, at Monte San Giorgio, in the same stratigraphic unit the modern morphology of G. triassicus co-occurs with the ancient one represented by Dasyleptus triassicus (Archaeognatha: dagger Monura). Comparing these two types of body organization we provide a new reconstruction of the possible character evolution leading towards modern archaeognathan forms, suggesting the acquisition of novel features in a lineage of apterygote insects during the Permian or the Lower Triassic
Giant coercivity and high magnetic blocking temperatures for N2 3â radical-bridged dilanthanide complexes upon ligand dissociation
Single-molecule magnets typically only retain information in the presence of an applied magnetic field and at very low temperatures. Here, Demir, Long and co-workers design N2 3â radical-bridged dilanthanide complexes that exhibit giant coercivities and 100-s magnetic blocking temperatures of up to 20âK
In silico design of pseudo D5h actinide based molecular magnets: role of covalency in magnetic anisotropy
Hypoanthraconaia: a new genus of non-marine bivalve molluscs from the Early Permian of Far East Russia
Seeking magneto-structural correlations in easily tailored pentagonal bipyramid Dy(III) single-ion magnets
The Role of the AP-1 Transcription Factors c-Fos, FosB, Fra-1 and Fra-2 in the Invasion Process of Mammary Carcinomas
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