Jeffrey A. Raymakers

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This methodological study aims at comparison of the practical usefulness of several parameters of body sway derived from recordings of the center of pressure (CoP) with the aid of a static force platform as proposed in the literature. These included: mean displacement velocity, maximal range of movement along x- and y-co-ordinates, movement area, planar(More)
The synthesis of bulk amounts of high quality single-walled carbon nanotubes (SWNTs) is accomplished by optimizing the chemical compositions and textural properties of the catalyst material used in the chemical vapor deposition (CVD) of methane. A series of catalysts are derived by systematically varying the catalytic metal compounds and support materials.(More)
In this retrospective study the epidemiology of hip fractures in The Netherlands was evaluated. The number of hip fractures over the period 1972–1987 was collected from the Dutch Centre for Health Care Information (Stichting Informatiecentrum voor de Gezondheidszorg, SIG). The demographic data were collected from the Dutch Centre for Statistics (Centraal(More)
The mortality rate and causes of death after a hip fracture were studied in 493 consecutive patients with a hip fracture. All patients were treated in three hospitals in Utrecht, The Netherlands. The mortality rate following hip fractures is high and age dependent. Forty-five patients, 38 women and 7 men, died during the period of hospitalization (9.1%).(More)
For the objective assessment of the severity and progression of osteoporotic deformities of the spine, a mathematical model has been developed which permits evaluation of a single set of radiographs of the spine without reference to absolute values of vertebral height. The model was based on measurements of anterior, central and posterior heights of the(More)
Bone-loss in glucocorticoid-induced osteopenia is most evident in trabecular bone such as the vertebrae. Bone mineral content (BMC) measurements of the spine were prospectively studied, comparing the preventive effect of calcium (500 mg a day) and calcium plus Vitamin D (4000 IU on alternate days) during long-term corticosteroid treatment. A small increase(More)
Three patients, two women aged 79 and 80 and a man aged 84, showed symptoms of cognitive impairment caused by primary hyperparathyroidism. Parathyroidectomy lead to a marked improvement in the symptoms. The incidence of primary hyperparathyroidism increases with age. Most patients only show slight symptoms. In addition, clinical symptoms in elderly patients(More)
The aim of the study was to investigate the usefulness of urinary fluoride excretion in evaluating fluoride therapy. In a prospective study, 35 patients with osteoporosis were treated for about 44 months with a mean dosage of 31.4 mg fluoride ion per day. Urinary fluoride excretion and serum alkaline phosphatase activity were measured at 3-month intervals.(More)
For the rapid evaluation of calcium absorption in human subjects several isotopic tests have been proposed. Among them, the double isotope test based on the concurrent oral and intravenous administration of calcium isotopes seems the most reliable. However, the computations involved in this test, a deconvolution of the two specific-activity functions(More)