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Biomedical subjects

C Cornwell

Publications and source records attributed to C Cornwell.

9 recordsLinked to original sources
PubMed2001

Gas chromatographic technologies for the analysis of essential oils.

Essential oil analysis has basically had one technical goal: to achieve the best possible separation performance by using the most effective, available technology of the day. The result achieved from this may then be used to answer the research or industrial analysis questions which necessitated the analysis. This may be for comparative purposes, where one oil is contrasted with other(s) for quality control or investigation of adulteration, to discover new components, or to characterise the chemical classes of compounds present. Clearly, today the analyst turns to chromatography as the provider of separation and then may supplement that with mass spectrometry to aid identification. The power of GC-MS means that advances in both the separation technique, and improvements in mass spectrometry detection - along with improved data handling tools - will immediately be relevant to the essential oil area. This present review outlines the developmental nature of instrumental approaches to essential oil analysis using gas chromatography. Mass spectrometry will be included to the extent that it represents the hyphenation of choice for most analysts when analysing essential oils. Thus single-column and multi-dimensional analysis will be covered, as will sample handling or introduction techniques prior to the analysis step, where these techniques provide some measure of separation. The recent demonstration of comprehensive gas chromatography will be discussed as the potentially most powerful separation method for essential oils. This brief review is not intended to be a comprehensive dissertation on the field of essential oil analysis since that would require sufficient space to occupy a book in its own right. Rather, it will outline selected considerations and developments, to help explain where new technology has been applied to advantage in this field.

Chromatography, Gas↗
PubMed2001

Inhibition of maximal voluntary isokinetic torque production following stretching is velocity-specific.

Recent research has shown that a regimen of stretching provides an acute inhibition of maximal force production by the stretched muscle group. To further characterize this phenomenon, the effect of an acute stretching regimen on maximal isokinetic knee-extension torque at 5 specific movement velocities (1.05, 1.57, 2.62, 3.67, and 4.71 rad x s(-1)) was examined in 10 men and 5 women (22-28 years). Each person's 5 baseline maximal isokinetic knee-extension torques (dominant leg) were measured on a Cybex NORM dynamometer. Following the baseline torque measurements, the participants stretched the dominant quadriceps for 15 minutes using 1 active and 3 passive stretching exercises. Once the stretching exercises were completed, the maximal torque measurements were repeated. Poststretch maximal torque at 1.05 rad x s(-1) was significantly reduced (p < 0.05) from 218 +/- 47 Nm (mean +/- SD) to 199 +/- 49 Nm (7.2% decrease). At 1.57 rad x s(-1), a similar decrease (p < 0.05) was also seen (204 +/- 48 Nm vs. 195 +/- 47 Nm; 4.5% decrease), but at the other velocities (2.62, 3.67, and 4.71 rad x s(-1)), poststretch maximal torque was unaltered (p > 0.05). It appears, therefore, that the deleterious impact of stretching activities on maximal torque production might be limited to movements performed at relatively slow velocities.

Adult↗
PubMed1997

The psychiatric advanced practice nurse with prescriptive authority: role development, practice issues, and outcomes measurement.

Within the rapidly changing health care system, there is an increased need for professionals who can provide cost-effective primary health care for mentally ill patients. This article discusses the role of the Psychiatric Advanced Practice Nurse (APN) with Prescriptive Authority as a cost-effective, high-quality component of comprehensive mental health care delivery. Historical aspects of the development of the Nurse Practitioner (NP) role are discussed, as well as issues specific to the role in psychiatric nursing. The implementation of this role at Rochester is described, followed by recommendations for studying the impact of the psychiatric NP on care delivery, including process and outcome variables.

Cost-Benefit Analysis↗
PubMed1997

L-Glutamate and serotonin are endogenous in squid chromatophore nerves

Colour changes in cephalopods are controlled by complex organs termed chromatophores whose radial muscles are directly innervated from the brain. In the squids Alloteuthis subulata and Loligo vulgaris, light microscopy of silver- or Methylene-Blue-stained preparations shows that each muscle is innervated by 2-6 nerves running along its length. An electron microscope (EM) study shows that most of these nerves contain 50 nm diameter electron-lucent vesicles organised into numerous synapses along the muscle. Their size and appearance is consistent with their containing l-glutamate (l-Glu). Usually there is one nerve on each muscle containing 95 nm diameter electron-dense vesicles that are not organised into synapses. Such vesicles, whose appearance is consistent with their containing serotonin (5-HT), are never found co-localised with the small, clear vesicles. Topically applied l-Glu causes the radial muscles to contract (and the chromatophore to expand), even after chronic denervation; this effect is blocked by the glutamate antagonists CNQX and DNQX. In contrast, topically applied 5-HT (or its agonists 8-OH-DOPAT and -methyl 5-HT) induces relaxation of precontracted muscle. Incubation with antibodies to l-Glu (Lg-A), using peroxidase anti-peroxidase/diaminobenzidine visualisation, produces specific staining along the radial muscles like that seen with silver. Antibodies to 5-HT produce similar specific staining. When sections of skin that had stained positively with Lg-A in the light microscope are examined at the EM level, it is seen that such staining is confined to nerve axons. These results, showing that l-Glu and 5-HT are endogenous in the nerves innervating squid chromatophores and that the radial muscles contain receptors for both substances, suggest that l-Glu is an excitatory transmitter at squid chromatophore muscles. The way in which 5-HT acts to relax the muscles, however, remains to be established.

Journal Article↗
PubMed1992

Disease conditions affecting common seals (Phoca vitulina) around the Scottish mainland, September-November 1988.

Common seal populations around the Scottish coast were less severly devastated by phocine distemper than those on the Continent. Nevertheless, over a 4-month period, 59 common seals were examined postmortem. The macroscopic and histopathological lesions are described. Forty-two per cent of these seals were considered to be suffering from phocine distemper. Serology on 29 of the 59 seals was undertaken and the results are discussed in relation to the histopathological findings. Bordetella bronchiseptica proved to be an important secondary invader in phocine distemper virus infected seals. Verminous pneumonia was shown to be a frequent problem, particularly in juveniles.

Animals↗
PubMedDate not supplied

Altruism and creative expression in a long-term older adult psychotherapy group.

This article describes the use of altruism and creative expression in an older adult psychotherapy group. These interventions, for which theoretic rationale and clinical examples are provided, are designed to decrease feelings of powerlessness that accompany life changes; to facilitate insight into feelings, coping, and preventative strategies for adaptation to change and loss; and to combat stereotypes, false beliefs, and myths imposed by a youth-oriented society. An integrated therapeutic model, combining psychodynamic, supportive, and cognitive/behavioral approaches, was used in the design of this group intervention for older adults. The authors, using rich clinical examples coupled with discussion of related theoretic background, provide the psychotherapist with an interesting perspective on this unique use of group psychotherapy with older adults. Such groups can provide a context within which to offer these patients the hope of relatedness, the opportunity to gain independence, and a heightened sense of integrity and possibility in one's later years.

Adaptation, Psychological↗