Management and outcomes in children with sinogenic intracranial abscesses.

Objective: To report our experience of sinogenic intracranial abscesses in the paediatric population and to guide medical and surgical management.

Methods: All children with sinogenic intracranial abscesses presenting to a large university teaching hospital over a five-year period were included in the study. Data on clinical presentation, radiological findings, microbiology, medical and surgical management and follow-up were recorded and analysed.

An unusual presentation of herpes infection in the head and neck.

Herpes simplex virus (HSV) is among a spectrum of viruses known to affect the upper aerodigestive tract. Gingivostomatitis and pharyngitis are the most common clinical manifestations of first-episode HSV infection, whereas recurrent herpes labialis is the most common clinical manifestation of reactivation HSV infection. Herpetic viral infections seldom attack the larynx.

Endoscopic or external approach revision surgery for pharyngeal pouch following primary endoscopic stapling: which is the favoured approach?

This study aimed to assess outcomes of revision endoscopic stapling and external excision of pharyngeal pouch. A 5-year prospective study was performed on all patients requiring revision pouch surgery following primary endoscopic stapling. Data were collected retrospectively.

Screen-printable silver pastes with metallic nano-zinc and nano-zinc alloys for crystalline silicon photovoltaic cells.

Silver metallization pastes for crystalline silicon PV cells containing nanosized metallic zinc were found to be superior to commercial pastes containing micrometer-sized metallic zinc and micrometer sized zinc oxide in terms of efficiency and firing window. Efficiency performance decreases as the size of the particles increases: nano-Zn > 3.6 μm Zn > 4.

A rearrangement of 1,1-linked four-membered rings to bicyclic bridgehead five-membered rings: a phosphorus turn.

Novel rearrangements of 2,3,2',3'-tetra-tert-butyl-4,4'-bis-trimethylsilanyloxy-1,2,1',2'-tetrahydro-[1,1']biphosphetyl (7) to 1,2,5,6-tetra-tert-butyl-3,7-bis-trimethylsilanyloxy-1H,5H-[1,2]diphospholo-[1,2-a][1,2]diphosphole (9) and of 3,4,3,4-tetra-tert-butyl-[1,1']biphosphetanyl-2,2'-dione (10) to 2,3,6,7-tetra-tert-butyl-tetrahydro-[1,2]diphospholo[1,2-a][1,2]diphosphole-1,5-dione (12) were observed during sublimation at 150 degrees C in 0.1 mm vacuum. The C-P-C internal angles of the four-membered rings, which reflect steric strain in (7), were 71.

A stable enol in small ring systems: clear differentiation between penta- and tri-valency of phosphorus atoms.

The first stable enols in 1,2-dihydrophosphetes and were synthesized and structurally characterized with intermolecular hydrogen bonds to phosphoryl groups in 10-membered dimeric structures; in contrast, trivalent analogue exists in keto-form, where such stabilization by hydrogen bonds is not feasible.

A tetra-substituted chrysene: orientation of multiple electrophilic substitution and use of a tetra-substituted chrysene as a blue emitter for OLEDs.

The first tetra-substituted non-fused chrysene, 3,6,9,12-tetrakis(4-tert-butylphenyl)chrysene with blue electroluminescence at 450 nm, and with a radiance of 500 cd m(-2), was synthesized by a two-step procedure: direct bromination of chrysene in trimethyl phosphate, followed by palladium-catalyzed cross-coupling of tetrabromochrysene and tert-butylphenylboronic acid .

Highly sterically hindered olefins: a case of E- and Z-di-tert-butyl alpha,beta-unsaturated acids.

Use of a superbase in the Favorskii rearrangement of 12 resulted in the synthesis of highly sterically hindered olefins, (E)-2- tert-butyl-4,4-dimethyl-pent-2-enoic acid (4) and (Z)-2- tert-butyl-4,4-dimethyl-pent-2-enoic acid (3).

A stabilized beta-oxaphosphoniumbetaine: an elusive zwitterion.

A beta-oxaphosphoniumbetaine stabilized by two tert-butyl groups at the phosphonium part of the betaine and two trifluoromethyl groups at the carbon adjoined to the oxa part of the betaine was isolated and structurally characterized. Additional stabilization results from the solvation of the betaine by a parent phosphonium salt, as in 4, or by protonation with methanol, as in 10. According to X-ray analysis, the betaine exhibits a sterically strained "gauche" conformeric form, with torsion angles in the P-C-C-O moiety of 32.