394 research outputs found

    Preserved decision making ability in early multiple sclerosis

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    Background : The purpose of this study was to assess decision making in patients with multiple sclerosis (MS) at the earliest clinically detectable time point of the disease. Methods : Patients with definite MS (n = 109) or with clinically isolated syndrome (CIS, n = 56), a disease duration of 3 months to 5 years, and no or only minor neurological impairment (Expanded Disability Status Scale [EDSS] score 0-2.5) were compared to 50 healthy controls using the Iowa Gambling Task (IGT). Results : The performance of definite MS, CIS patients, and controls was comparable for the two main outcomes of the IGT (learning index: p = 0.7; total score: p = 0.6). The IGT learning index was influenced by the educational level and the co-occurrence of minor depression. CIS and MS patients developing a relapse during an observation period of 15 months dated from IGT testing demonstrated a lower learning index in the IGT than patients who had no exacerbation (p = 0.02). When controlling for age, gender and education, the difference between relapsing and non-relapsing patients was at the limit of significance (p = 0.06). Conclusion : Decision making in a task mimicking real life decisions is generally preserved in early MS patients as compared to controls. A possible consequence of MS relapsing activity in the impairment of decision making ability is also suspected in the early phase of M

    Determinants of smoking and cessation in older women

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    BACKGROUND: although the benefits of quitting smoking even at an advanced age have been proved, few campaigns target the older population. The goals of this study were to analyse the characteristics of older women smokers help and support those wanting to quit. METHODS: we assessed the determinants of smoking cessation in a prospective cohort study performed in 7,609 older women. A questionnaire about smoking habits was sent to the 486 eligible smokers. Smoking dependence and smokers' readiness to quit was assessed. Participants who had quit smoking during follow-up were asked about their previous reasons for quitting and the methods used to quit. RESULTS: 372 women of the 424 (88%) responded to our questionnaire and were included. The most common reasons for smoking were relaxation, pleasure, and habit. Major obstacles to quitting smoking were 'no benefit to quitting at an advanced age', 'smoking few or "light" cigarettes yields no negative health consequences', and 'smoking does not increase osteoporotic risk'. During the 3-year follow-up period, 57 of the 372 (15%) women successfully quit smoking. Being an occasional smoker (OR=2.4) and reporting 'quitting is not difficult' (OR=3.7) were positively associated with having recently quit smoking. Only 11% of successful cessations were reported to have received physician advice. CONCLUSIONS: these data illustrate the specific smoking behaviour of older women, suggesting that cessation interventions ought to be tailored to these characteristics. Willingness to quit was associated with a low education level. The most frequent obstacles to quitting were all based on incorrect information

    On the chromatic aberration of microlenses

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    The optical properties of plano-convex refractive microlenses with low Fresnel Number (typically FN < 10) are investigated. It turns out that diffraction effects at the lens aperture limit the range of the effective focal length. The upper limit of the focal length is determined by the diffraction pattern of a pinhole with equal diameter. In addition achromatic microlenses can be realized because refraction and diffraction have opposing effects on the focal length. Gaussian beam propagation method has been used for simulation. The presented results are of relevance for applications, where microlenses with small apertures and long focal lengths are used, for example, Shack Hartmann wavefront sensors or confocal microscopes

    Processing and characterization of a new biodegradable composite made of a PHB/V matrix and regenerated cellulosic fibers

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    In this study, a biodegradable composite consisting of a degradable continuous cellulosic fiber and a degradable polymer matrix—poly(3-hydroxybutyrate)-co-poly(3-hydroxyvalerate (PHB/V with 19% HV)—was developed. The composite was processed by impregnating the cellulosic fibers on-line withPHB/V powder in a fluidization chamber. The impregnated roving was then filament wound on a plate and hot-pressed. The resulting unidirectional composite plates were mechanically tested and optically characterized by SEM. The fiber content was 9.9 ±0.9 vol% by volumetric determination. The fiber content predicted by the rule of mixture for unidirectional composites was 13.8 ±1.4 vol%. Optical characterization showed that the fiber distribution was homogeneous and a satisfactory wetting of the fibers by the matrix was achieved. Using a blower to remove excess matrix powder during processing increased the fiber content to 26.5 ±3.3 vol % (volumetric) or 30.0 ±0.4 vol% (rule of mixture). The tensile strength of the composite parallel to the fiber direction was 128 ±12 MPa (10 vol% fiber) up to 278 ±48 MPa (26.5 vol% fiber), compared to 20 MPa for the PHB/V matrix. The Young's modulus was 5.8 ±0.5 GPa (10 vol% fiber) and reached 11.4 ±0.14 GPa (26.5 vol% fiber), versus 1 GPa for the matri

    Alignment of Multiple Configurations Using Hierarchical Models

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    We describe a method for aligning multiple unlabeled configurations simultane- ously. Specifically, we extend the two-configuration matching approach of Green and Mardia (2006) to the multiple configuration setting. Our approach is based on the in- troduction of a set of hidden locations underlying the observed configuration points. A Poisson process prior is assigned to these locations, resulting in a simplified formu- lation of the model. We make use of a structure containing the relevant information on the matches, of which there are different types to take into account. Bayesian inference can be made simultaneously on the matching and the relative transformations between the configurations. We focus on the particular case of rigid-body transformations and Gaussian observation errors. We apply our method to a problem in chemoinformatics: the alignment of steroid molecules. Supplementary materials are available online

    Combining bone resorption markers and heel quantitative ultrasound to discriminate between fracture cases and controls

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    Summary: This nested case-control analysis of a Swiss ambulatory cohort of elderly women assessed the discriminatory power of urinary markers of bone resorption and heel quantitative ultrasound for non-vertebral fractures. The tests all discriminated between cases and controls, but combining the two strategies yielded no additional relevant information. Introduction: Data are limited regarding the combination of bone resorption markers and heel quantitative bone ultrasound (QUS) in the detection of women at risk for fracture. Methods: In a nested case-control analysis, we studied 368 women (mean age 76.2 ± 3.2years), 195 with low-trauma non-vertebral fractures and 173 without, matched for age, BMI, medical center, and follow-up duration, from a prospective study designed to predict fractures. Urinary total pyridinolines (PYD) and deoxypyridinolines (DPD) were measured by high performance liquid chromatography. All women underwent bone evaluations using Achilles+ and Sahara heel QUS. Results: Areas under the receiver operating-characteristic curve (AUC) for discriminative models of the fracture group, with 95% confidence intervals, were 0.62 (0.56-0.68) and 0.59 (0.53-0.65) for PYD and DPD, and 0.64 (0.58-0.69) and 0.65 (0.59-0.71) for Achilles+ and Sahara QUS, respectively. The combination of resorption markers and QUS added no significant discriminatory information to either measurement alone with an AUC of 0.66 (0.60-0.71) for Achilles+ with PYD and 0.68 (0.62-0.73) for Sahara with PYD. Conclusions: Urinary bone resorption markers and QUS are equally discriminatory between non-vertebral fracture patients and controls. However, the combination of bone resorption markers and QUS is not better than either test used alon

    Combining clinical factors and quantitative ultrasound improves the detection of women both at low and high risk for hip fracture

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    Summary: We hypothesized that combining clinical risk factors (CRF) with the heel stiffness index (SI) measured via quantitative ultrasound (QUS) would improve the detection of women both at low and high risk for hip fracture. Categorizing women by risk score improved the specificity of detection to 42.4%, versus 33.8% using CRF alone and 38.4% using the SI alone. This combined CRF-SI score could be used wherever and whenever DXA is not readily accessible. Introduction and hypothesis: Several strategies have been proposed to identify women at high risk for osteoporosis-related fractures; we wanted to investigate whether combining clinical risk factors (CRF) and heel QUS parameters could provide a more accurate tool to identify women at both low and high risk for hip fracture than either CRF or QUS alone. Methods: We pooled two Caucasian cohorts, EPIDOS and SEMOF, into a large database named "EPISEM”, in which 12,064 women, 70 to 100years old, were analyzed. Amongst all the CRF available in EPISEM, we used only the ones which were statistically significant in a Cox multivariate model. Then, we constructed a risk score, by combining the QUS-derived heel stiffness index (SI) and the following seven CRF: patient age, body mass index (BMI), fracture history, fall history, diabetes history, chair-test results, and past estrogen treatment. Results: Using the composite SI-CRF score, 42% of the women who did not report a hip fracture were found to be at low risk at baseline, and 57% of those who subsequently sustained a fracture were at high risk. Using the SI alone, corresponding percentages were 38% and 52%; using CRF alone, 34% and 53%. The number of subjects in the intermediate group was reduced from 5,400 (including 112 hip fractures) and 5,032 (including 111 hip fractures) to 4549 (including 100 including fractures) for the CRF and QUS alone versus the combination score. Conclusions: Combining clinical risk factors to heel bone ultrasound appears to correctly identify more women at low risk for hip fracture than either the stiffness index or the CRF alone; it improves the detection of women both at low and high ris

    Management and prognosis of status epilepticus according to hospital setting: a prospective study.

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    BACKGROUND: The treatment of status epilepticus (SE) is based on relatively little evidence although several guidelines have been published. A recent study reported a worse SE prognosis in a large urban setting as compared to a peripheral hospital, postulating better management in the latter. The aim of this study was to analyse SE episodes occurring in different settings and address possible explanatory variables regarding outcome, including treatment quality. METHODS: Over six months we prospectively recorded consecutive adults with SE (fit lasting five or more minutes) at the Centre Hospitalier Universitaire Vaudois (CHUV) and in six peripheral hospitals (PH) in the same region. Demographical, historical and clinical variables were collected, including SE severity estimation (STESS score) and adherence to Swiss SE treatment guidelines. Outcome at discharge was categorised as "good" (return to baseline), or "poor" (persistent neurological sequelae or death). RESULTS: Of 54 patients (CHUV: 36; PH 18), 33% had a poor outcome. Whilst age, SE severity, percentage of SE episodes lasting less than 30 minutes and total SE duration were similar, fewer patients had a good outcome at the CHUV (61% vs 83%; OR 3.57; 95% CI 0.8-22.1). Mortality was 14% at the CHUV and 5% at the PH. Most treatments were in agreement with national guidelines, although less often in PH (78% vs 97%, P = 0.04). CONCLUSION: Although not statistically significant, we observed a slightly worse SE prognosis in a large academic centre as compared to smaller hospitals. Since SE severity was similar in the two settings but adherence to national treatment guidelines was higher in the academic centre, further investigation on the prognostic role of SE treatment and outcome determinants is required
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