Correction: Aromaticity and sterics control whether a cationic olefin radical is resistant to disproportionation.

[This corrects the article DOI: 10.1039/D0SC00699H.].

Aromaticity and sterics control whether a cationic olefin radical is resistant to disproportionation.

We elucidate why some electron rich-olefins such as tetrathiafulvalene (TTF) or paraquat (1,1'-dimethyl-4,4'-bipyridinylidene) form persistent radical cations, whereas others such as the dimer of ,'-dimethyl benzimidazolin-2-ylidene (benzNHC) do not. Specifically, three heterodimers derived from cyclic (alkyl) (amino) carbenes (CAAC) with ,'-dimethyl imidazolin-2-ylidene (NHC), ,'-dimethyl imidazolidin-2-ylidene (saNHC) and -methyl benzothiazolin-2-ylidene (btNHC) are reported. Whereas the olefin radical cations with the NHC and btNHC are isolable, the NHC compound with a saturated backbone (saNHC) disproportionates instead to the biscation and olefin.

Endoscopic ventriculostomy versus shunt operation in normal pressure hydrocephalus: diagnostics and indication.

In contrast to shunt operation the indication for an endoscopic ventriculostomy in patients diagnosed for normal pressure hydrocephalus is not scientifically established. From September 1997 to March 1999 we operated on 36 patients diagnosed for normal pressure hydrocephalus. Diagnosis was established by means of the intrathecal lumbar or ventricular infusion test, the cerebrospinal fluid tap test and MRI-CSF flow studies pre- and post-operatively.

Clinical experiences with the dual-switch valve in patients with normal pressure hydrocephalus.

In patients with normal pressure hydrocephalus (NPH) we compared the postoperative results reference to the implanted valve type. In 117 patients diagnosed with normal pressure hydrocephalus there was placement of 47 Cordis Standard valves (CSV), 20 Cordis Orbis Sigma valves type I (OSV) and 50 Miethke Dual-switch valves (DSV). Ninety-five patients (36/19/40) were re-evaluated.

The use of decompressive craniectomy for the management of severe head injuries.

The aim of Neurosurgical care is to minimise the secondary brain damage that occurs after a severe head injury. This includes the evacuation of an intracranial space occupying haematoma, the reduction of intracranial volume, external ventricular drainage with hydrocephalus, and conservative therapy to reduce intracranial pressure (ICP) and to maintain tissue oxygen p(ti)O2. When conservative treatment fails, a decompressive craniectomy might be successful in lowering ICP.