Biomedical subjects

Peter J Martin

Publications and source records attributed to Peter J Martin.

7 recordsLinked to original sources

PubMed2005

Willow growth in response to nutrients and moisture on a clay landfill cap soil. I. Growth and biomass production.

The growth and biomass production by willow (Salix viminalis L.) was studied in lysimeters containing Oxford clay landfill cap soil with different amendments, bulk densities and watering regimes. Three years from planting, stem biomass in well-watered plants was least (0.28 kg plant(-1)) with high bulk density soil (1480 kg m(-3)) and no nutritional amendment but was increased 10-fold (2.53 kg plant(-1)) by reducing soil bulk density (1200 kg m3) and adding amendments. In comparison, on a sandy loam soil it was 6.23 kg plant(-1). There were similar differences in number of stems plant(-1), stem basal area plant(-1) and plant leaf area which can be attributed to low nitrogen and phosphorus levels in Oxford clay. Water stress reduced stem biomass production by 26-37% and caused higher root:stem ratios. These were also higher on Oxford clay than on the sandy loam. Successful biomass production from willow on Oxford clay landfill caps will therefore require nutritional amendment.

Biomass↗

PubMed2005

Willow growth in response to nutrients and moisture on a clay landfill cap soil. II: Water use.

Water use by willow (Salix viminalis L.) was studied in lysimeters containing clay landfill cap and sandy loam soils under different watering and amendment regimes. With plentiful water and amendments, seasonal ET increased annually and was highest in the sandy loam, increasing from 360 l plant(-1) in the establishment year to almost 1200 l plant(-1) in the third year. Seasonal ET was highly correlated with leaf area duration. Amendment of Oxford clay resulted in increases in plant leaf area, dry matter production and seasonal ET. Water stress reduced seasonal ET by 10-14% in the second year and 25-41% in the third. Water use efficiency was low for the un-amended clay treatment (1.4 g kg(-1)) but was similar in the amended clay (5.0 g kg(-1)) and sandy loam (4.9 g kg(-1)). This highlights the interdependence of water use and biomass production in willow.

Biomass↗

PubMed2005

Increased dissolution rate and bioavailability through comicronization with microcrystalline cellulose.

Micronization is a commonly used enabling technology to improve the bioavailability of compounds where absorption is dissolution rate limited. However, decreasing particle size often results in increased Van der Waals' interactions and electrostatic attraction between particles. This causes agglomeration of particles, thereby compromising the increase in surface area gained by micronization. Comicronization with excipients has been reported to offer significant advantages over neat micronization. The present work describes the comicronization of a model compound CI-1040 at a high drug load that shows an increase in the dissolution rate and bioavailability in male Wistar rats. Physicochemical characterization of the comicronized and neat micronized material is presented to help explain the in-vitro and in-vivo data.

Animals↗

PubMed2005

Symbolic interactionism and the concept of power.

Symbolic interactionism is often represented as a perspective which is limited by its restriction to 'micro' aspects of social organization. As such, it is allegedly unable to adequately conceptualize 'macro' phenomena such as social structure, patterns of inequality, and power. Such a view is routinely presented in undergraduate textbooks. This paper contests such a view through a consideration of the concept of power. We argue that the interactionist research tradition does show a fundamental concern with power phenomena, and that a reconsideration of the concept is timely in light of theoretical developments in sociology more generally. An increasing concern with the analysis of culture, the continuing influence of Foucault, the development of feminist perspectives, and the emerging consensus around neo-Weberian thought have all contributed to a renewal of interest in themes long ago explored by interactionists. As examples we suggest that interactionist studies in the fields of deviance and education have been concerned above all with the authoritative imposition of consequential identities, i.e., with the social processes through which power is enacted and institutionalized in real situations. Such developments have led some to argue that interactionism has now been incorporated into the mainstream of sociology. We conclude, however, by arguing that such a view runs the risk of granting to orthodox sociological thought a legitimacy which is analytically unwarranted, and which fails to recognize the alternative theoretical and philosophical foundations of symbolic interactionist thought.

Education↗

PubMed2002

Dissolution testing of a poorly soluble compound using the flow-through cell dissolution apparatus.

Dissolution of Pfizer Compound PD198306, a poorly soluble compound, was studied in 25 mM pH 9 sodium phosphate solution with 0.5% SLS using the flow-through cell dissolution apparatus. Unmicronized and micronized drug powders were tested. Several methods of loading the drug powder into the flow-through dissolution cells and their impact on dissolution were investigated. The influence of flow rate of the dissolution medium on the rate and extent of dissolution were studied. PD198306 has poor wettability even in the presence of 0.5% SLS. It was found that loading the drug powder into the dissolution cell in the form of a suspension provided the best dissolution profile in terms of the rate and extent of dissolution. The flow rate of 4 ml/min resulted in good particle size discrimination.

Flow Cytometry↗

PubMed2002

A comparison of the occurrence and nature of vocal symptoms in two groups of Icelandic teachers.

Research suggests that teaching activities involve a high risk of developing voice disorders. The aim of this study is to examine the possible difference in the occurrence and nature of vocal symptoms in two groups of teachers-head teachers (N = 43), including both principals and assistant head teachers, and teachers of physical education (N = 43)--and to investigate the possible role of gender. The questionnaire results indicate that demands on the voice for P.E. teachers and head teachers are different. The findings suggest that (i) demands influence the occurrence and nature of reported vocal symptoms, (ii) that teachers of physical education are at a greater risk of developing voice problems, and (iii) that female P.E. teachers are at particular risk.

Adult↗

PubMed2002

Integration of acupuncture into the oncology clinic.

PURPOSE/OBJECTIVE: Patients with cancer or symptoms referable to cancer therapy were offered acupuncture as potential palliation of their symptoms. This paper describes the physical integration of the discipline into the Oncology Clinic, and patient perspectives on its availability and efficacy. PATIENTS AND METHODS: Between August 1999 and May 2000, 123 patients with varying symptoms received acupuncture in our Center's Radiation and Medical Oncology Clinics and Breast Health Center. These patients had 823 visits during this time period. A practice outcome analysis was performed on patients receiving therapy between 1 January 2000 and 30 April 2000. The 89 patients treated during this interval had 444 total visits. In June and July 2000, a questionnaire was administered by phone to 79 of these patients (89%). Standard allopathic care continued while patients were receiving acupuncture. RESULTS: Major reasons for referral included pain (53%), xerostomia (32%), hot flashes (6%) and nausea/loss of appetite (6%). Patients had a mean of five acupuncture visits (range 1-9). Most patients (60%) showed at least 30% improvement in their symptoms. About one-third of patients had no change in severity of symptoms. There were no untoward effects reported related to the acupuncture. When analysed by diagnosis, these values persist. Irrespective of response to therapy, 86% of respondents considered it 'very important' that we continue to provide acupuncture services. CONCLUSION: Acupuncture may contribute to control of symptoms for cancer patients. Expansion of providers, continued patient follow-up, optimization of techniques and prospective objective measurement of response continue in our clinic.

Acupuncture Therapy↗