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Advances in simulation technology are fueling a paradigmatic shift in how medicine will be taught and practiced in the future. Current simulators range from simplified part task trainers to fully immersive virtual environments. We are on the verge of training platforms that provide realistic representations of medical and surgical scenarios that engage learners in a manner that approximates reality. This article reviews the rationale for developing advanced virtual environments and details the technologies that are currently available. Immersive environments using virtual reality, herein reviewed, include Cave Automated Virtual Environments, Distributive Virtual Environments for collaborative learning over the internet (Project TOUCH), Serious Games for medical education (PULSE and 3DiTeams), and a Wide Area Virtual Environment. The ultimate role of these technologies in surgical education remains to be determined but will undoubtedly play an important part in the future.

Presents an advice column about gardening. Plants ideal for hanging baskets during winter; Ways to prevent Michaelmas daisies from powdery mildew; Availability of apples in England.

No abstract available for this article.

Analysis of desmethylmethsuximide by high-performance liquid chromatography (HPLC) is described. After adding an internal standard (IS), 200 μl of plasma was buffered to pH 4.5 and extracted with dichloroethane. The organic solvent was then evaporated to dryness and the residue reconstituted in 100 μl of mobile phase prior to injecting a 20 μl aliquot onto a Hypersil 5 MOS column, which was eluted with acetonitrile/acetate buffer (pH 5.5) 36:64 vol/vol. Constituents were separated in ∼8 min. Using this method, down to 1.0 mg/L of desmethylmethsuximide in plasma can be accurately determined. The method is suitable for therapeutic monitoring of desmethyl-methsuximide in patient samples.

Data are presented for the serum levels of 2-ethyl-2-phenylmalon-amide (PEMA) in patients receiving anticonvulsant medication. Statistical analysis of these data indicates that the serum level of PEMA, which is a metabolite of primidone, is affected not only by the dose of primidone but also by the serum levels of other prescribed anticonvulsant drugs. In particular, phenobarbitone is shown to be a major perturbation upon the PEMA serum level.

The analysis of clobazam and its metabolite desmethylclobazam by high-performance liquid chromatography is described. After adding an internal standard 500 μl of plasma is extracted under basic conditions into dichloroethane. The organic solvent is then evaporated to dryness and the residue reconstituted in 100 μl of mobile phase prior to injecting an aliquot (30 μl) onto a Hypersil 5 MOS column, which is eluted with acetonitrile/acetate buffer (pH 5.4) 40:60 vol/vol. The components are separated in approximately 12 min. Using this method, 15 μ L−1of clobazam and 30 μ L−1of desmethylclobazam can be detected. The method is suitable for the therapeutic monitoring of these two drugs in patient samples.

1 The information available from the literature and from a prospective survey of ibuprofen overdose being undertaken by the London centre of the National Poisons Information Service (NPIS) was examined utilizing the Generalized Linear Interactive Modelling (GLIM) statistical computing package.2 This confirmed that timed ibuprofen plasma concentrations were related to the symptoms of tachycardia, dizziness, tinnitus, ocular symptoms and coma/stupor as well as to reversible renal impairment and plasma hepatic enzyme elevation.3 The best model of the relationship between symptomatic toxicity and timed ibuprofen plasma concentrations, was an exponential equation in time. Because of the lack of specificity or sensitivity in this model, and absence of demonstrable clinical advantages from its application, we do not recommend its use as a guide to predict toxicity.4 However analysis of a larger information base utilizing similar methodology could, by increasing the statistical power of the resultant model, provide a useful means of predicting ibuprofen toxicity.5 A previously postulated relationship between post-ingestion ibuprofen plasma concentrations and toxicity was not confirmed.

Experience during 14 years of prescription only use indicates that the non-steroidal anti-inflammatory drug (NSAID) ibuprofen is of low toxicity in acute overdose. In August 1983 ibuprofen was licensed for over-the-counter (OTC) use in the UK and it was recognised that this change could have an impact upon the epidemiology of analgesic overdose in this country. The London centre of the National Poisons Information Service (NPIS) began a new prospective survey of ibuprofen overdose at the time of OTC release. The first 2 years of this survey detected a marked increase in enquiries concerning ibuprofen overdose but there was no evidence to contradict the former claims of low toxicity. The importance of continued monitoring is stressed.

A Lyot–Öhman filter for imaging near the solar He i 1083-nm line is described. Fast and continuous spectral tunability is provided by nematic liquid crystals. This solid-state filter has a free spectral range of 2.35 nm and a spectral resolution of 0.135 nm at the operating wavelength of 1083 nm. A wide-fielded design was used for both static and electro-optic retarder elements, facilitating use in fast imaging systems. A first-light He i image of the Sun is presented.

A method for predicting scattering coefficients in the atmospheric windows from 1.0 μ to 15.0 μ is presented. The method avoids the assumptions that the index of refraction and the aerosol distribution are constants over the range of relative humidity values. Relative humidity is taken as the independent variable with the aerosol distribution and index of refraction dependent upon the value of the relative humidity. A two-component continental and maritime aerosol distribution is used. Although strictly applicable to the 1.0–15.0 μ wavelength region, the calculations are extended with a lesser degree of accuracy into the visible region so that comparisons with measured data may be made.

An interferometric method has been developed to determine the linear coefficient of thermal expansion of optical materials that are available only in short sample lengths (1.5 cm or less). The method utilizes the simple fringe pattern resulting from a thin air wedge formed between two fused-quartz (fused-silica) optical flats; the top flat is supported by the sample by means of a fused-quartz screw. The expansion of the material is determined by relating its change of length to the measured change of fringe spacing, as temperature is changed. Three different techniques for controlling the temperature of the sample are discussed. Measurements have been made in the temperature range 0°–90°C for various optical materials: single crystals, polycrystals, and glasses.

The surgical availability of the mediastinum has stimulated interest in lesions of this area, but a review of the literature leads to confusion more than to clarity. The boundaries of the mediastinum vary from those stated by Maier,1 who does not include neurogenic tumors because they are in the costovertebral gutter, and not the true mediastinum, through Peabody and others,2 who include the middle mediastinum in the anterior portion and divide the mediastinum into superior and inferior compartments, each with an anterior and a posterior portion. The boundaries accepted by most authors will be used in this article and be delineated later.Blades,3 Harrington,4 and Laipply5 reviewed this subject, and their combined statistics show that 75% of the anterior mediastinal tumors are of teratoid origin, 52% of the tumors of the middle mediastinum are bronchogenic cysts, 90% of all posterior mediastinal tumors are neuroblastomas, and

Atmospheric transmittance spectra from 0.56 μ to 10.7 μ, obtained over a 25-km horizontal path at sea level, are presented. The sources were six 150-cm diam carbon arc searchlights. A radiometrically calibrated spectrometer equipped with a NaCl prism and a thermocouple detector was used to record the spectral distribution of the radiation transmitted through the atmosphere. The transmittance spectra were obtained for values of precipitable water vapor ranging from 21.5 cm to 43.3 cm. From these spectra the selective transmittance of four atmospheric windows was measured. A plot of selective transmittance as a function of the square root of the precipitable water vapor for the four windows shows that the transmittance in these windows is well described by the statistical model of band absorption.

Atmospheric absorption spectra obtained over a 25-km, horizontal, sea level path in the Cape Kennedy area are presented. Six 150-cm diam carbon arc searchlights positioned from 11 m to 17 m above the ground were used as sources of continuous radiation. Solar spectra obtained from sea level are traced above the corresponding horizontal path spectra for comparison. The spectral region covered is 0.68 μ to 4.86 μ and the spectral resolution varies over this region from about 0.6 × 10^−4μ to 60 × 10^−4μ. The amount of water vapor in the path varied from 9 to 39 precipitable cm.

Abstract: Dodecanedioic acid, currently available from elaborate synthesis utilizing petrochemical feedstock, was synthesized fromVernonia galamensis oil via an efficient, relatively simple three-reaction sequence that involved the room temperature oxidation of 12,13-epoxystearic acid. The first and second steps of the reaction scheme were saponification and hydrogenation, both of which were almost quantitative. The third reaction, involving chromic acid oxidation of the resulting epoxy acid, afforded greater than 50% of the theoretical yield of dodecanedioic acid (>95% purity, m.p. 123–125°C; lit. m.p. 128–130°C).

Information is presented for the serum concentrations during haemodialysis of primidone, phenobarbitone, and phenylethylmalonamide (PEMA) in a patient with renal failure receiving chronic primidone therapy. The concentrations of drug and metabolites fell during haemodialysis, but PEMA concentrations were above normal at all times. The average renal clearance of PEMA during 6 h of dialysis was found to be 84.7 ± 4.6 ml min−1.

During a solar eclipse the Moon's shadow moves at supersonic speed through the Earth's atmosphere. Chimonas and Hines1,2suggested that the resultant cooling of the atmosphere would generate a bow wave of atmospheric gravity waves, which may be detectable as a travelling ionospheric disturbance or as a ground-level atmospheric pressure variation. Although the evidence for gravity waves in the ionosphere from a solar eclipse is still weak, they may have been detected3. Ground-level pressure changes during solar eclipses occur near the region of totality4, but the measured wave velocity and period do not agree with that of the predicted disturbance5,6. We now report the detection of a ground-level pressure wave detected at three stations in India and one station in Java, Indonesia. These data may provide the first direct observation of eclipse generated gravity waves over a very long range. The most distant station in India was 6,600 km from the eclipse centre line. The microbarometer recordings indicate that a wave disturbance was recorded at each station with a quasi-period of ∼4 h and a wave velocity of ∼320 m s−1.

A study has been carried out to evaluate the shielding effectiveness of a knife-edge ridge situated in the near-field region of a large-diameter antenna, and examples of the computed results are presented in graphical form. In addition an approximate formula, of accuracy within 3 dB under specified conditions, is also presented. A flat-Earth profile is assumed, and the effects of rounding of the diffracting edge and of vegetation are excluded.

The purpose of this paper is to report a case of Kartagener's syndrome. The occurrence of situs inversus and bronchiectasis was first noted in 1904 by Siewert,4 who described a case of situs inversus in a 20-year-old youth. The triad of situs inversus, bronchiectasis, and paranasal sinusitis has been more fully described by Adams and Churchill.1 Kartagener2 reported 11 cases in 1933 and 1935.The reason for the occurrence of bronchiectasis in patients who have situs inversus has never been explained, but the associated higher incidence has been clearly shown.3 REPORT OF CASE The patient is a 14-year-old white girl who entered the hospital on July 7, 1958, with a history of productive cough "all her life." The sputum was described as yellow and not foul. The patient's mother had had no viral disease during her pregnancy. The patient has one brother and one sister, and