Discontinuation of anticoagulants and occurrence of bleeding and thromboembolic events in vitamin K antagonist users with a life-limiting disease.

Background: Data on risks and benefits of long-term anticoagulants in patients with a life-limiting disease are limited. This cohort study aims to describe (dis)continuation of anticoagulants and incidences of bleeding and thromboembolic events in vitamin K antagonist (VKA) users with a life-limiting disease.

Methods: Data from five Dutch anticoagulation clinics were linked to data from Statistics Netherlands and the Netherlands Cancer registry.

Hydride Rebound: A Frustrated Lewis Pair (FLP)-Type Cooperative Mechanism for H2 Activation by a Potassium Aluminyl Compound.

Combining experiment and theory, the mechanisms of H2 activation by the potassium-bridged aluminyl dimer K2[Al(NON)]2 (NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tertbutyl-9,9-dimethylxanthene) and its monomeric K+-sequestered counterpart have been investigated. These systems show diverging reactivity towards the activation of dihydrogen, with the dimeric species undergoing formal oxidative addition of H2 at each Al centre under ambient conditions, and the monomer proving to be inert to dihydrogen addition. Noting that this K+ dependence is inconsistent with classical models of single-centre reactivity for carbene-like Al(I) species, we rationalize these observations instead by a cooperative frustrated Lewis pair (FLP)-type mechanism (for the dimer) in which the aluminium centre acts as the Lewis base and the K+ centres as Lewis acids.

Metathesis chemistry of inorganic cumulenes driven by B-O bond formation.

The reaction chemistry of an unprecedented 'inorganic cumulene' - featuring a five-atom BNBNB chain - towards C[double bond, length as m-dash]O (and related) multiple bonds is disclosed. In marked contrast to related all-carbon systems, the intrinsic polarity of the BNBNB chain (featuring electron-rich nitrogen and electron-deficient boron centres) enables metathesis chemistry with electrophilic heteroallenes such as CO and with organic carbonyl compounds. Transfer of the borylimide unit to [CO], [CS], [PP{(NDippCH)}] and [C(H)Ph] moieties generates (boryl)N[double bond, length as m-dash]C[double bond, length as m-dash]X systems (X = O, S, PP{(NDippCH)}, C(H)Ph), driven thermodynamically by B-O bond formation.

A Crystalline NiX Complex.

High-valent nickel species are implicated as intermediates in industrially relevant chemical transformations and in the catalytic cycles of metalloenzymes. Although a small number of tetravalent NiX complexes have been crystallographically characterized, higher nickel valence states have not been identified. Here we report a stable, crystalline NiX complex, Ni(BeCp) (; cyclopentadienyl anion (Cp)), formed by the insertion of zerovalent nickel into three Be-Be bonds.

First records of the roughskin dogfish Centroscymnus owstonii in the greater Antilles, central Caribbean Sea, Western Atlantic Ocean.

The roughskin dogfish Centroscymnus owstonii, a deep-sea shark, has a patchy global distribution, with most knowledge stemming from incidentally captured specimens. Using a deep-sea remote lander video system, we observed multiple C. owstonii individuals alive on the footage at 1054 m off Little Cayman, Cayman Islands, Western Atlantic Ocean, marking, to our knowledge, the first record of the species in the Greater Antilles, central Caribbean Sea, while also adding a new species locality record for the Cayman Islands.