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Biomedical subjects

S A Walton

Publications and source records attributed to S A Walton.

5 recordsLinked to original sources

Theophrastus on Lyngurium: medieval and early modern lore from the classical lapidary tradition.

The ancient philosopher Theophrastus (c.371-285 BC) described a gemstone called lyngurium, purported to be solidified lynx urine, in his work De lapidibus ('On Stones'). Knowledge of the stone passed from him to other classical authors and into the medieval lapidary tradition, but there it was almost always linked to the 'learned master Theophrastus'. Although no physical example of the stone appears to have been seen or touched in ancient, medieval, or early modern times, its physical and medicinal properties were continually reiterated and elaborated as if it did 'exist'. By the seventeenth century, it began to disappear from lapidaries, but with no attempt to explain previous authors' errors since it had never 'existed' anyway. In tracing the career of lyngurium, this study sheds some light on the transmission of knowledge from the classical world to the Renaissance and the changing criteria by which such knowledge was judged.

Folklore↗

The mathematical and military sciences in Renaissance England.

The Renaissance saw the evolution of troop management, fortification and artillery into 'mathematical' sciences and those who practiced these tasks into 'mathematical practitioners'. These terms have been allowed to imply that these areas were deeply theoretical, whereas they varied from theoretical to simply numerical. Gunnery, in particular, tended towards the latter. Practitioners of the simpler mathematics, however, gained by being able to connect their action to the more impressive study of 'the mathematicks'. Future work must recognize more critically the distinction inherent in the term 'mathematical' when applied to the arts of the Renaissance.

England↗

Nanoscale iron(III) oxyhydroxy aggregates formed in the presence of functional water-soluble polymers: models for iron(III) biomineralisation processes.

Superparamagnetic clusters of iron(III) oxyhydroxide in the form of poorly crystalline ferrihydrite (formally, 5Fe2O3 x 9H2O) have been synthesised in the presence of the polymers polyvinyl alcohol (PVA), polyacrylic acid (PAA) and alginic acid. The solutions have been characterised by viscosity studies and the resultant arrays isolated from these solutions have been imaged under an electron microscope and their magnetic properties determined by 57Fe-Mössbauer spectroscopic studies at 293 and 77 K and magnetisation measurements at 293 and 5 K. The magnetic data show that the iron(III) oxyhydroxy particles are superparamagnetic. All preparations show hysteretic behaviour with coercive fields being approximately half or less than half of that of ferrihydrite (3.4 kOe) and values of magnetic moment per iron particle less than that of ferrihydrite. Nanoscale aggregates (2-4 nm) are formed in the presence of PVA and PAA while, with alginic acid, extended branch-like structures are observed, their formation being facilitated by the comparatively rigid polysaccharide chain, a process related to iron biomineralisation in diverse biological systems.

Acrylic Resins↗

Superiority of lithium over verapamil in mania: a randomized, controlled, single-blind trial.

BACKGROUND: Both case reports and small controlled studies suggest the efficacy of verapamil in the treatment of mania. METHOD: Forty patients with DSM-IV mania were studied in a 28-day randomized, controlled, single-blind trial of either lithium or verapamil. RESULTS: The patients receiving lithium showed a significant improvement on all rating scales (Brief Psychiatric Rating Scale [BPRS], Mania Rating Scale [MRS], Global Assessment of Functioning [GAF], and Clinical Global Impression [CGI]) compared with those receiving verapamil. The mean MRS score at Day 28 in the lithium group was significantly lower than that in the verapamil group (17.47 vs. 24.43, respectively; F = 6.17, df = 1, p = .018). A similar pattern was seen with the BPRS (12.68 vs. 20.57; F = 10.69, df = 1, p = .002), CGI (2.31 vs. 3.33; F = 6.05, df = 1, p = .019), and GAF (43.52 vs. 52.31; F = 4.36, df = 1, p = .044) (ANCOVA). CONCLUSION: This study suggests that lithium is superior to verapamil in the management of acute mania.

Acute Disease↗

Passive marijuana usage and water intoxication.

This article reports a case of a 3-month-old male presenting with hyponatremic seizure and hypothermia. The presence of marijuana in the infant's urine was remarkable. An etiologic role for the drug is questioned. A review of the literature is provided and the hypothesis of child neglect in the genesis of water intoxication is explored.

Cannabis↗