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Biomedical subjects

I Spencer

Publications and source records attributed to I Spencer.

14 recordsLinked to original sources
PubMed2005

Hyaline membrane and neonatal radiology--Ian Donald's first venture into imaging research.

While he was working at the Royal Postgraduate Medical School, Ian Donald (later Regius Professor of Midwifery, University of Glasgow and a pioneer of diagnostic ultrasound) collaborated with Albert Claireaux and Robert Steiner on histological and radiological studies of hyaline membrane disease. In 1953, Donald and Steiner published thefirst radiological study of a series of cases. The success of this research stimulated Donald's interest in imaging technologies.

History, 20th Century↗
PubMed2003

Demonstration of fusion-evaporation and direct-interaction nuclear reactions using high-intensity laser-plasma-accelerated ion beams.

Heavy-ion induced nuclear reactions in materials exposed to energetic ions produced from high-intensity (approximately 5 x 10(19) W/cm(2)) laser-solid interactions have been experimentally investigated for the first time. Many of the radionuclides produced result from the creation of "compound nuclei" with the subsequent evaporation of proton, neutron, and alpha particles. Results are compared with previous measurements with monochromatic ion beams from a conventional accelerator. Measured nuclide yields are used to diagnose the acceleration of ions from laser-ablated plasma to energies greater than 100 MeV.

Journal Article↗
PubMed2003

Experimental study of proton emission from 60-fs, 200-mJ high-repetition-rate tabletop-laser pulses interacting with solid targets.

Measurements of proton emission have been made from a variety of solid targets irradiated by a 60-fs, 200-mJ, 7 x 10(18)-W cm(-2) laser system operating at 2 Hz. Optimum target conditions were found in terms of target material and thickness. For Mylar targets of thickness 20-40 microm, a maximum proton energy of 1.5 MeV was measured. For aluminum targets, a maximum energy of 950 keV was measured for 12 microm, and for copper, 850 keV for 12.5 microm.

Journal Article↗
PubMed2002

The decay of chlorine associated with the pipe wall in water distribution systems.

Free chlorine decay rates in water distribution systems for bulk and wall demands should be modelled separately as they have different functional dependencies. Few good quality determinations of in situ wall demand have been made due to the difficulty of monitoring live systems and due to their complexity. Wall demands have been calculated from field measurements at 11 locations in a distribution system fed from a single source. A methodology for the laboratory determination has been evolved and shown to give results that are similar to the in situ results. Pipe materials were classified as either having high reactivity (unlined iron mains) or low reactivity (PVC, MDPE and cement-lined ductile iron). The results indicate that wall decay rates for the former are limited by chlorine transport and for the latter by pipe material characteristics. The wall decay rate is inversely related to initial chlorine concentration for low reactivity pipes. In general, water velocity increases wall decay rates though the statistical confidence is low for low reactivity pipes. A moderate biofilm coating did not influence the wall decay rate for low reactivity pipes.

Biofilms↗
PubMed2000

Effect of the plasma density scale length on the direction of fast electrons in relativistic laser-solid interactions

The angular distribution of bremsstrahlung gamma rays produced by fast electrons accelerated in relativistic laser-solid interaction has been studied by photoneutron activation in copper. We show that the gamma-ray beam moves from the target normal to the direction of the k(laser) vector as the scale length is increased. Similar behavior is found also in 2D particle-in-cell simulations.

Journal Article↗
PubMed2000

Photonuclear physics when a multiterawatt laser pulse interacts with solid targets

When a laser pulse of intensity 10(19) W cm(-2) interacts with solid targets, electrons of energies of some tens of MeV are produced. In a tantalum target, the electrons generate an intense highly directional gamma-ray beam that can be used to carry out photonuclear reactions. The isotopes 11C, 38K, (62,64)Cu, 63Zn, 106Ag, 140Pr, and 180Ta have been produced by (gamma,n) reactions using the VULCAN laser beam. In addition, laser-induced nuclear fission in 238U has been demonstrated, a process which was theoretically predicted at such laser intensities more than ten years ago. The ratio of the 11C and the 62Cu beta(+) activities yields shot-by-shot temperatures of the suprathermal electrons at laser intensities of approximately 10(19) W cm(-2).

Journal Article↗
PubMed2000

Lessons from history: the politics of psychiatry in the USSR.

The political-economic base of society affects every aspect of it, including nursing and psychiatry. This can be demonstrated by making a historical analysis of societies with different political-economic systems. Psychiatry in the USSR took a different form to psychiatry in the West. Differences included the diagnostic categories used and treatments employed. This can be investigated by examining accounts of clinical practice. Soviet psychiatry was also used for the systematic incarceration of political dissidents. Some commentators have drawn on the Soviet experience and used it to support an argument that psychiatry operates as a form of social control in the West as well as the USSR. This article shows how psychiatric abuse in the USSR was a historically specific response to a particular situation. Therefore some of the conclusions about Western psychiatry extrapolated from the Soviet experience are unsupportable. Whatever the role of psychiatry in the West, its mechanism is qualitatively different to that which existed in the USSR. In order to understand why Soviet medical workers were co-opted into the conscious abuse of psychiatry, it is essential to understand the specific nature of the USSR. This does not necessarily allow generalizations about Western psychiatry to be made from the Soviet experience. As psychiatric nurses, we can also learn from a particularly tragic period of psychiatry's history.

Humans↗
PubMed1995

Towards early defibrillation--a nurse training programme in the use of automated external defibrillators.

It is essential that all health care professionals are regularly trained in the practice of basic life support (BLS). In most cases of cardiac arrest, the chances of a favourable outcome depend not only on efficient BLS, but also on the early use of defibrillation. In a hospital environment, the first responders are most likely to be members of the nursing staff. The potential advantage of these personnel being able to perform early defibrillation, as well as BLS, is considerable. We describe an initiative in which instruction in the use of automated external defibrillators (AEDs) was introduced into routine BLS training sessions, with the aim of developing this capability. Using specifically-acquired training aids, 43 nurses and nine other members of the non-medical staff were trained in 12 teaching sessions over a period of 4 months. Refresher training was carried out after 6 months and 37 nurses were retrained during six sessions using a similar syllabus. The programme was well-received by all students, and a higher than expected level of motivation and competence was achieved. Throughout retraining all nurses appreciated the key importance of early defibrillation. We conclude that, although the initial workload is high, it is entirely feasible to augment BLS training for health care professionals with instruction in the use of AEDs. We recommend that this potentially life-saving tuition programme be widely adopted.

Automation↗
PubMed1995

A prospective analysis of critical incidents attributable to anaesthesia.

The purpose of the study was an accurate and comprehensive prospective analysis of all untoward anaesthetic events and their sequelae, within a general hospital over a period of 1 year. We identified five system sets into which each of these critical incidents could be categorised. We also recorded data pertaining to the severity of the disturbance or event, the monitor that first identified the problem and the affect, if any, of the incident upon the patient. We found a critical incident rate of 6.68%, or one in 15 anaesthetic procedures performed. By far the majority of incidents were rapidly detected and effectively managed, with a morbidity rate of only 0.53%. The application of minimum monitoring standards was strongly reinforced. The presence of an anaesthetist throughout the period of the whole anaesthetic was shown to be the most effective component of these standards. The audit identified a trend for junior anaesthetists in particular to have a higher incidence of problems with the airway and circulation and for these to be associated with increased morbidity. This prompted revised supervision and training strategies for our junior anaesthetists.

Anesthesia↗
PubMed1994

Performance of the Baxter disposable patient-controlled analgesia infusor under hyperbaric conditions.

Hyperbaric oxygen treatment may require the concurrent administration of drugs. A study was performed to assess the suitability of the infusor device from the Baxter Patient-Controlled Analgesia system, for drug delivery during hyperbaric therapy. Thirty infusor devices were used to deliver 5% dextrose, 50% dextrose or propofol solutions under conditions 1 and 2.3 atmospheres of pressure. The increased pressure caused an increase in flow of 4.27%, 1.79% and 9.84% for 5% dextrose, propofol and 50% dextrose respectively.

Analgesia, Patient-Controlled↗
PubMed1992

A guide to the use of electronic bulletin boards.

Data transfer between distant computers is potentially a rapid and efficient method of gathering and disseminating information. Bulletin Boards can coordinate this activity but their benefit is proportional to the number of users. The initial telephonic connection between computers and the subsequent data transfer is complex; this review attempts to explain some of the theory and problems involved.

Computer Communication Networks↗