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. RESULTS: We identified 27 children aged 12.9 ± 3.4 years of which 56% were male. Fourteen (52%) children had extradural abscesses, nine (33%) subdural abscesses and four (15%) parenchymal abscesses. Early sinus drainage procedures were performed on 24 (89%) patients, and the same number required neurosurgical drainage. Streptococcus milleri was isolated in 18 (67%) cases. An initial conservative neurosurgical approach failed in 50% of cases where trialled, and was associated with longer length of stay (p = 0.025). In comparison to extradural abscesses, subdural abscesses were more likely to present with neurological deficits (p < 0.001) and reduced consciousness (p = 0.018), and required multiple neurosurgical procedures (p < 0.001), longer stays (p = 0.017), and had greater morbidity at six months (p = 0.017). A third of children had significant morbidity at six months, which included cognitive and behavioural problems (25%), residual hemiparesis (19%) and expressive dysphasia (7%). There were no mortalities. CONCLUSION: Sinusitis complicated by intracranial abscess remains a contemporary problem. We demonstrate good outcomes with an early combined rhinological and neurosurgical approach. S. milleri is identified as the causative organism in the majority of cases, and empirical antimicrobial treatments should reflect this.

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. Laryngeal disorders provoked by the herpes virus are characterised by a large spectrum of presentations and polymorphisms, and can simulate mucous lesions such as an extensive laryngeal neoplasm (supraglottic tumour). We report a case of a 69-year-old woman, smoker, who presented with a large ulcerated supraglottic mass mimicking laryngeal cancer, requiring emergency tracheostomy for worsening stridor, which turned out to be an HSV laryngitis superimposed onto an underlying Streptococcus A lower respiratory tract infection. The patient was treated for Streptococcus A infection and her symptoms resolved following treatment. Patient's tracheotomy tube was removed on follow-up appointment.

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. Eighteen patients underwent revision pouch surgery. In seven patients, pouch size was down-graded from 3 to 2, and these were stapled endoscopically. Two leaks resulted. Eleven patients with grade 1 or 3 pouches underwent external excision of pouch, with no post-operative complications. As per results external excision of pouch is safe for grade 1 and 3 pouches. It avoids risking redundant mucosa and recurrence of symptoms which can complicate stapling and enables a myotomy to be performed to reduce cricopharyngeal hypertonicity. The highest predictable success is with grade 2 pouches, whose size is amenable to adequate endoscopic stapling. However, the "staple over staple" effect of revision stapling leads to unpredictable fibrosis, which can contribute to risk of perforation.

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 > 4.4 µm Zn. Advanced electron microscopy techniques were used to investigate the interfacial microstructure between the front-side contact and the Si emitter of nanosized zinc additive based cells fired at temperatures from below to above optimal. These microstructural observations confirmed the possibility of a tunneling mechanism of current flow (a "nano-Ag colloid assisted tunneling" model) in the absence of Ag crystallites. Contact resistance maps were used to guide sampling, leading to a better understanding of the relationship between microstructure and contact resistance. Low contact resistance and higher cell efficiency, especially at under- and overfiring temperature conditions, are due to more uniform silicon nitride etching obtained through the use of nanosized metallic zinc additives.

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 71.9(2) degrees and 77.9(1) degrees; the C-P-P internal angles of the five-membered rings of 9 were 90.88(6) degrees and 93.02(6) degrees after rearrangement. Reaction of 7 with metallic caesium provided the caesium salt of 3,4-di-tert-butyl-3,4-dihydro-phosphet-2-ol (15), which is the first example of a 2lambda-3-phospha-1-enolate being incorporated into four-membered ring. Due to its large size, the caesium cation has a rare coordination mode with both the phosphorus and oxygen atoms of the 2lambda-3-phospha-1-enolate, forming infinite polymeric chains in the solid state of 15. Two tert-butyl groups in the vicinal positions of compounds 7, 9, 10, 12 and 15 dictate the gauche conformations in compounds 7, 9, 10, 12 and 15, enforcing this stereoselectivity around the C-C-C portion of the rings in the enlargement reaction.

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 32.2 degrees for 4 and 28.1 degrees for 10. The P...O separations of 3.121 A for 4 and 3.086 A for 10 are just under the sum of the O and P van der Waals radii (3.32 A). The fast H/D exchange of alpha hydrogen atoms to the phosphonium center was observed in the solution of 10 in deuterium oxide and MeOH-d4. The beta-oxaphosphoniumbetaine has long been suspected as an intermediate in the Wittig reaction, but this is the first time a stabilized derivative has been isolated.