Search

Context. TRACE 171 Å observations of transverse loop oscillations on May 13, 2001 have been studied by De Moortel & Brady (2007). They found hints of 3 periodicities present in this event.

Driven by enormous clinical need, interest in peripheral nerve regeneration has become a prime focus of research and area of growth within the field of tissue engineering. While using autologous donor nerves for bridging peripheral defects remains today's gold standard, it remains associated with high donor site morbidity and lack of full recovery. This dictates research towards the development of biomimetic constructs as alternatives. Based on current concepts, this review summarizes various approaches including different extracellular martices, scaffolds, and growth factors that have been shown to promote migration and proliferation of Schwann cells. Since neither of these concepts in isolation is enough, although each is gaining increased interest to promote nerve regeneration, various combinations will need to be identified to strike a harmonious balance. Additional factors that must be incorporated into tissue engineered nerve constructs are also unknown and warrant further research efforts. It seems that future directions may allow us to determine the “missing link”.

Recent Government policy has been strongly in favour of encouraging entrepreneurship and partnerships with industry. A flagship project backed by £68 m was launched by Gordon Brown as Chancellor of the Exchequer in 1999. Due diligence exercises by the DTI failed to ensure that value for money was obtained. What had been planned and announced as an educational charity became a Limited Company and the ban on using the money for commercial spin-outs was waived. There was imperfect quality control of projects and little control over costing. There appear to be funding lessons both for Government and for universities at a time when it is proposed to charge students top-up fees, for the sum given away by the Treasury here for one badly-supervised project represents the top-up fees of over 20,000 students.

Two methods for the resolution of tramadol are described. One uses the active pharmaceutical ingredient (API), tramadol hydrochloride as input material. The other utilises the crude free base obtained from the Grignard reaction on tramadol Mannich base. Both resolutions use mandelic acid; the cost and process implications of each approach are discussed.

A versatile route to single enantiomer verapamil from readily available raw materials is described. The key intermediate, 4-cyano-4-(3,4-dimethoxyphenyl)-5-methyl hexanoic acid (verapamilic acid), was resolved efficiently with α-methyl benzylamine. Stereochemical integrity at the quarternary carbon centre was preserved through subsequent steps to give either (R)-or (S)-verapamil in good overall yield. This sequence incorporated a selective borane-mediated reduction of a tertiary amide. Process scale-up to the pilot plant has been demonstrated successfully for the resolution step.

The development of a short, safe and enantioselective route for the preparation of (R)-aminoglutethimide is described. The process was designed for economic large-scale manufacture of the bulk drug substance to acceptable quality standards, to allow clinical evaluation of the single enantiomer over the existing racemate. (R)-Aminoglutethimide was prepared from 1-chloro-4-nitrobenzene using a six-stage synthetic sequence, via chemoresolution of key intermediate racemic 4-cyano-4-(4-nitrophenyl)hexanoic acid using (−)-cinchonidine. The process allowed for preparation of several kilograms of the precursor (R)-nitroglutethimide, to cGMP at pilot-plant scale, along with demonstration of the final hydrogenation step to (R)-aminoglutethimide in the laboratory. This route avoids the problems of hazardous nitration technology, and therefore regio-isomer contamination of the product, associated with other procedures. The resolution chemistry described represents an improvement on literature procedures. Optimisation of the asymmetric Michael addition offers an attractive alternative approach.

MEDIEVAL LOGICSP. 0 . LEWRY (ed.), The rise of British logic. Acts of the sixth European Symposium on mediaeval logic and semantics, Balliol College, Oxford, 19-24 June 1983. Toronto: Pontifical Institute of Mediaeval Studies, 1985. xii+421 pp. $34.50.L. M. ,DE RIJK, La philosophie au moyen cige. Translated from the Dutch by P.Swiggers, Leiden: E. J. Brill, 1985. xi + 244 pp. 50 Hfl.RAIMUNDUS LULLUS, Die neue Logik. Logica nova. Textkritisch herausgegeben von Charles Lohr. Übersetzt von Vittorio Hösle und Walburga Büchel. Mit einer Einführung von Vittorio Hosle. (Lateinisch-deutsch.) Hamburg: Felix Meiner Verlag, 1985. xciv + 3 17s. 64DM.PAULUS VENETUS, Logica parva. Translation of the 1472 edition, with introduction and notes by Alan R. Perreiah. Miinchen and Wein: Philosophia Verlag, 1984. 372 pp. DM 138.E. J. ASHWORTH, Studies in post-medieval semantics. London: Variorum Reprints, 1985. x + 342 pp. £32.00.D. GABBAY and F. GUENTHNER (eds.), Handbook of philosophical logic. Volume 2: Extensions of classical logic. Dordrecht, Boston and Lancaster: D. Reidel Publishing Company, 1984. xi + 779 pp. Dfl. 31 5/$12O.OO/£80.25.THOMAS M. SEEBOHM, Philosophie der Logik. Freiburg: Alber, 1984. 364 pp. DM 74.WERNER STELZNER, Epistemische Logik. Zur logischen Analyse von Akzeptationsformen.Berlin: Akademie-Verlag, 1984. 206 pp. No price stated.JAMES BOGEN and JAMES E. MCGUIRE (eds.), How things are: studies in predication and the history and philosophy of science. (Philosophical studies series in philosophy, Volume 29.) Dordrecht: D. Reidel, 1985. 345 pp. US $46.00.GEORG HENRIK VON WRIGHT, Truth, knowledge, and modality. (Philosophical papers, Volume 3.) Oxford: Basil Blackwell, 1984. ix + 155 pp. 15.00.JEAN VAN HEIJENOORT, Selected essays. Naples: Bibliopolis, 1985. 166 pp. No price stated.H. WANG, Beyond analytic philosophy. Doing justice to what we know. Cambridge (Massachusetts) and London: The MIT Press, 1986. xii + 273pp. No price stated.TEXTBOOKSR. L.VAUGHT, Set theory: an introduction. Boston, Basel, Stuttgart: Birkhäuser, 1985. x+141 pp. SFr. 76.W. H. NEWTON-SMITH, Logic: An introductory course. London, Melbourne and Henley: Routledge and Kegan Paul, 1985. x+ 230 pp. £5.95 (paper).MISCELLANEOUSPIERRE DUHEM, Medieval cosmology. Edited and translated by Roger Ariew.Chicago and London: University of Chicago Press, 1985. xxxi+ 601 pp. £24.75.DAVID A. WHITE, Logic and ontology in Heidegger. Columbus: Ohio State University Press, 1985. xiv + 245 pp. $22.50.J. W. DEGEN, Systeme der kumulativen Logik. Miinchen und Wien: Philosophia Verlag (Reihe Analytica), 1983. 265pp. DM 128.GABRIELE LOLLI, La ragioni jisiche e la dimonstrazioni matematiche. Bologna: I1 Mulino, 1985. 365 pp. 30,000 lire.

This paper presents a working classification of haemoglobin disorders, describes the pathological and clinical features of the most important conditions and discusses their occupational implications.

Aspects of health were studied in a sample of factory workers who changed their pattern of working from 'fortnight about' to three advancing shifts. Within the same factory and doing similar work there was a comparison group who were working permanent days only. The change in shifts was associated with more difficulty with sleep, more indigestion, higher alcohol consumption, reduced alertness and a worse social life. There was more minor psychiatric disturbance in those who worked three shifts than in those who worked days only.

Germination requirements, root development, phenology, and the effects of moisture—saturated soils were studied in Aristida longiseta and Agropyron spicatum. Agropyron germinated well at temperatures of 20°—22°C, but Aristida showed little response until temperatures were increased to 40°C. Prior stratification at 0°C had no appreciable effect on germination of either species. Rapid primary root elongation enabled Aristida to establish itself in droughty habitats, but saturated soils strongly inhibited its growth. In the field A. longiseta starts growth late in the spring, develops at a rapid rate, and flowers 10 days later than A. spicatum. The seed of Aristida matures slowly and is shed in September. Fall regrowth, which occurs normally in A. spicatum, is rare in A. longiseta. The hypothesis is developed that excessive grazing has so reduced the abundance of A. spicatum that A. longiseta has been able to replace it and form long—lived communities.

DURING the latter part of 1938, a high-pressure cloud chamber designed by the late Prof. E. J. Williams was constructed to investigate certain phenomena concerned with cosmic ray mesons. It was hoped that by using high pressures, giving a long sensitive-time, that mesons would be observed coming to the end of their range in the cloud chamber. Four such examples have been obtained1. A similar example was also found by B. J. Williams and G. E. Roberts using a large cloud chamber working at atmospheric pressure2. In each case, the meson is observed to come to rest and then to decay with the emission of a β-particle. From these results, it is estimated that the proportion of slow mesons (β < 0.25) in cosmic radiation at sea-level is about 0.05 per cent. In these experiments, no evidence has been found of the disintegration of nuclei by mesons as reported recently by D. H. Perkins3, and by C. F. Powell and G. P. S. Occhialini4. Little information concerning the frequency of such events at sea-level is available, and it was thought that it would be worth while to expose some photographic emulsions in the same room as the cloud chamber. Unfortunately, this work was interrupted by the War and only resumed a few months ago.

WE wish to draw attention to a novel and striking similarity between the physics of two apparently quite disparate situations—the behaviour of the interstellar medium and of water vapour in an atmospheric cloud.

EVIDENCE for the transformation of mesotrons into electrons was recently reported in these columns1. This was obtained by the use of the cloud chamber, and consisted in the observation of a fast electron track emanating from the end of the track of a mesotron. What appears to be another instance of this phenomenon was recently observed in this laboratory, though on account of the tracks being rather old and accompanied by other old tracks the photograph is not as good as the earlier one. Apart from a further indication of the frequency of occurrence of the phenomenon, it does not give any new information.