Biomedical subjects

C Martineau

Publications and source records attributed to C Martineau.

At least 19 recordsLinked to original sources

PubMed2006

19F high magnetic field NMR study of beta-ZrF4 and CeF4: from spectra reconstruction to correlation between fluorine sites and 19F isotropic chemical shifts.

High magnetic field and high spinning frequency one- and two-dimensional one-pulse MAS 19F NMR spectra of beta-ZrF4 and CeF4 were recorded and reconstructed allowing the accurate determination of the 19F chemical shift tensor parameters for the seven different crystallographic fluorine sites of each compound. The attributions of the NMR resonances are performed using the superposition model for 19F isotropic chemical shift calculation initially proposed by Bureau et al. (Bureau, B.; Silly, G.; Emery, J.; Buzaré, J.-Y. Chem. Phys. 1999, 249, 85-104). A satisfactory reliability is reached with a root-mean-square (rms) deviation between calculated and measured isotropic chemical shift values equal to 1.5 and 3.5 ppm for beta-ZrF4 and CeF4, respectively.

Journal Article↗

PubMed2006

Multinuclear high-resolution NMR study of compounds from the ternary system NaF-CaF2-AlF3: from determination to modeling of NMR parameters.

27Al and 23Na NMR satellite transition spectroscopy and 3Q magic-angle-spinning spectra are recorded for three compounds from the ternary NaF-CaF2-AlF3 system. The quadrupolar frequency nuQ, asymmetry parameter etaQ, and isotropic chemical shift deltaiso are extracted from the spectrum reconstructions for five aluminum and four sodium sites. The quadrupolar parameters are calculated using the LAPW-based ab initio code WIEN2k. It is necessary to perform a structure optimization of all compounds to ensure a fine agreement between experimental and calculated parameters. By a comparison of experimental and calculated values, an attribution of all of the 27Al and 23Na NMR lines to the crystallographic sites is achieved. High-speed 19F NMR MAS spectra are recorded and reconstructed for the same compounds, leading to the determination of 18 isotropic chemical shifts. The superposition model developed by Bureau et al. is used, allowing a bijective assignment of the 19F NMR lines to the crystallographic sites.

Journal Article↗

PubMed2006

Fear-avoidance beliefs about back pain in patients with subacute low back pain.

The fear-avoidance beliefs of patients with subacute low back pain (LBP) considered at risk for chronic disabling LBP are not well known. The objectives of this cross-sectional descriptive survey, conducted in secondary care practice, were to assess fear-avoidance beliefs about back pain in patients with subacute LBP and to seek an association between physician or patient characteristics and level of fear-avoidance beliefs. A total of 286 rheumatologists completed a self-administered questionnaire assessing physicians' demographic, professional data, personal history of back pain, and back pain fear-avoidance beliefs (on the Fear-Avoidance Belief Questionnaire [FABQ]) and 443 patients with sLBP completed one on pain, perceived handicap and disability (Quebec Back Pain Disability Scale), anxiety and depression (Hospital Anxiety Depression questionnaire), and back pain beliefs (FABQ). Mean FABQ scores for rheumatologists for physical activities (FABQ Phys) and occupational activities (FABQ Work) were 9.2+/-4.4 (range 0-21) and 16.7+/-6.9 (range 2-37), respectively, and patient scores were 16.7+/-5.2 and 19.3+/-12.4, respectively. A total of 68% of patients and 10% of physicians had a high rating on the FABQ Phys (>14). Patients' fear-avoidance beliefs about physical activity were associated with low level of education (odds ratio [OR] 4.19; 95% confidence interval [CI] 1.83-9.57), patients' perceived disability (OR 1.05; CI 1.03-1.07), and physicians' high FABQ Phys score (OR 5.92; CI 1.31-26.32). Here we show that fear-avoidance beliefs about back pain were high in patients with subacute LBP and their rheumatologists.

Acute Disease↗

PubMed2005

Outcome of subacute low back pain: influence of patients' and rheumatologists' characteristics.

OBJECTIVES: To assess the outcome of subacute low back pain, to identify the characteristics of patients and physicians which were related to outcome and to evaluate the influence of rheumatologists' beliefs about back pain on their following the guidelines for physical and occupational activity. METHODS DESIGN: a longitudinal descriptive survey. SETTING: a secondary care practice in France. PARTICIPANTS: 266 rheumatologists; 440 patients with subacute low back pain. OUTCOME MEASURES: the main outcome measure was persistence of back pain 3 months after baseline evaluation. A self-administered questionnaire for physicians assessed attitudes and beliefs about back pain [Fear-Avoidance Beliefs Questionnaire (FABQ)], and one for patients assessed pain, perceived handicap and disability (Quebec Scale), anxiety and depression (Hospital Anxiety Depression Questionnaire), and beliefs about back pain (FABQ). RESULTS: Forty per cent of patients had persistent low back pain at 3 months; 5.5% of these had sciatica. A total of 10% of rheumatologists and 68% of patients at baseline had a high FABQ physical score (phys; >14). Determinants of outcomes were work-related back pain [odds ratio (OR) = 3.37; 95% confidence interval (CI) 1.08-5.17], anxiety (OR = 2.41; 95% CI 1.44-4.09), sex (female OR = 2.03; 95% CI 1.30-3.18) and patients' beliefs about back pain at work (OR = 1.02; 95% CI 1.00-1.05). Physicians with high FABQ physical scores were less likely to follow guidelines on prescribing rest and occupational activity for back pain. CONCLUSION: Back pain commonly persists 3 months later in patients with subacute low back pain. Patients and rheumatologists still have negative beliefs about back pain. Rheumatologists' beliefs influence their following guidelines on physical and occupational activities. National education programmes about low back pain are needed in France.

Acute Disease↗

PubMed1997

A comparison of conventional microscopy, immunofluorescence microscopy and flow cytometry in the detection of Giardia lamblia cysts in beaver fecal samples.

A variety of domestic and wild animals are considered to be potential sources of giardiasis in humans. As a result, numerous studies have been reported on the prevalence of Giardia lamblia infection in animals. The majority of these surveys have involved various floatation techniques followed by conventional microscopy in order to detect cysts in fecal samples. Immunofluorescence microscopy has become popular in recent years for the detection of G. lamblia cysts in both clinical and environmental samples. This technique can be automated by combining it with flow cytometry. The present study represents a direct comparison of conventional microscopy, immunofluorescence microscopy, and flow cytometry in terms of their relative efficiency in the detection of G. lamblia cysts in beaver fecal samples. As a result of viewer fatigue, or low cyst concentrations, false negatives were common with conventional microscopy, leading to low prevalence estimates. By specifically targeting the cysts, immunofluorescence microscopy provided more reliable results in a shorter time than conventional methods. When flow cytometry was used in combination with immunofluorescence, a larger number of samples could be examined in a relatively short period of time. The results obtained indicated that this technique allowed for more consistent recognition than either conventional or immunofluorescence microscopy of positive samples containing smaller numbers of cysts.

Animals↗

PubMed1990