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D W Lane

Publications and source records attributed to D W Lane.

8 recordsLinked to original sources
PubMed2004

Determination of depth-dependent diffraction data: a new approach.

A direct method for determining powder diffraction data at specific depths from angle-dependent diffraction data is described. The method is non-destructive and only traditional data collections, where the angle of incidence is varied, are required. These angle-dependent spectra are transformed to give diffraction data arising from different depths, which may then be exploited using any conventional method. This is a novel approach as traditional methods are forced to tolerate the inherent depth averaging of grazing-angle diffraction, or only examine specific structural characteristics. In order to obtain depth-dependent X-ray diffraction data, a Fredholm integral equation of the first kind is solved using regularization techniques. The method has been validated by the generation of pseudo-experimental data having known depth profiles and solving the Fredholm integral equation to recover the solution. The method has also been applied to experimental data from a number of thin film systems.

Journal Article↗
PubMed1997

Iron pre-load for major joint replacement.

Patients undergoing total hip or knee replacement frequently receive blood transfusion. Homologous blood transfusion carries appreciable risks and should therefore be reduced to a minimum. We have investigated the use of preoperative oral iron supplements to optimize haemoglobin concentration and iron stores prior to surgery. All patients attending a preadmission clinic 4 weeks prior to primary hip or knee replacement had a haemoglobin measurement. If the haemoglobin concentration (Hb) was less than 12 g dL-1 they were given a four week course of ferrous sulphate. If it was greater than or equal to 12 g dL-1 they were randomized to a control group or given a supplementation course of ferrous sulphate. One hundred patients were seen. Of these 18 (18%) had haemoglobin less than 12 g dL-1 and 16 were treated with iron. The mean Hb was 10.8 g dL-1 and mean cell volume (MCV) 86. These patients increased their Hb by a mean 1.1 g dL-1 prior to admission (P = 0.008). MCV was the best predictor of response (r = -0.63, P < 0.02). This group dropped their haemoglobin by a mean 1.4 g dL-1 in the first post-operative week. In the study groups there was no significant preoperative rise in Hb. However, the control group dropped their Hb by a mean 1.3 g dL-1 in the week following surgery compared with 0.4 g dL-1 in the group which had received iron supplements (P < 0.001). We conclude that at least 18% of patients attending for hip or knee replacement in this region are frankly anaemic and benefit significantly from preoperative iron supplements over 4 weeks. Iron supplementation in patients without obvious anaemia protects against a fall in Hb during the immediate post-operative period, suggesting a widespread underlying depletion of iron stores in this group despite a normal Hb. Preoperative iron supplements may reduce transfusion requirements as part of a co-ordinated strategy in this group of patients.

Aged↗
PubMed1994

Viscosimetric effect of fibrinogen.

AIMS: To investigate the correlation between fibrinogen concentration and plasma and serum viscosity. METHODS: Measurements of paired plasma viscosity and serum viscosity were compared in 45 subjects with a considerable range of fibrinogen concentrations and serum viscosity. RESULTS: Plasma and serum viscosity correlated well with plasma fibrinogen in cases of normal serum viscosity, but not in cases of myeloma or macroglobulinaemia. When an exponential correlation between plasma and serum viscosity was used, fibrinogen showed a good correlation in both normal and abnormal conditions. CONCLUSIONS: There is an exponential correlation between plasma and serum viscosity which depends on the plasma fibrinogen concentration. This is in accordance with Arrhenius's formula for solutions of varying concentrations.

Blood Viscosity↗
PubMedDate not supplied

Some observations on the trace element concentrations in human dental enamel.

The concentration of trace elements has been measured for dental enamel from 86 healthy human teeth using particle-induced X-ray emission (PIXE). The majority of the teeth (n = 70) were collected from dentists in the county of Oxfordshire in the United Kingdom, although a smaller group (n = 16) were collected from Cornwall. The elements K, Ca, Mn, Fe, Co, Ni, Cu, Zn, Sr, Pb, and Hg have been detected and statistically analyzed by grouping according to sex, age, and geographical location. The concentrations of Fe and Cu were found to be lower in the teeth from female donors (P < 5%) and are believed to result from the continued burden of blood loss during menstruation. Strong positive correlations (P < 0.1%) were found between Ca, Co, Ni, and Zn for all groups; these elements were also found to exhibit a negative correlation (P < 1%) with age for teeth from female donors. This is believed to be related to decalcification during the menopause. Pb was found to exhibit a positive correlation (P < 5%) with age for both sexes, and is believed to substitute for Ca in the Ca hydroxy apatite (HAP) within the dental enamel.

Adolescent↗