Comparative investigation of stator-mounted permanent magnet machines under fault conditions

Here, machines having permanent magnets (PM) mounted in the stator are compared during fault operations such as armature winding short circuits. The magnet potential irreversible demagnetisation is also investigated due to the fact that the PMs are placed close to the armature coils (heat sources) and hence are prone to temperature-related demagnetisations. It is found that the doubly salient and flux reversal machines have inherently higher fault tolerant capabilities when compared with the switched-flux one. To the point of view of demagnetisation withstand capability, the doubly salient topology stands out as the most robust one while the switched flux is the weakest one

Health-related quality of life and cost of ambulatory care in osteoporosis: how may such outcome measures be valuable information to health decision makers and payers?

The objective was to quantify the outcome of osteoporosis (OP) in terms of health-related quality of life (HR-QOL) and cost of ambulatory care and to look at the association between these two outcomes variables. A cross-sectional health survey of 4800 Belgian individuals over the age of 45 years was used. Individuals having reported OP were retrieved and for each of them, at least two matched individuals for age, sex, residency location, and health insurance status were identified. All individuals were assessed with the SF-36. The two major health insurance providers furnished cost value for ambulatory care. HR-QOL and cost data were compared between the OP group and control group. Beta-coefficients from linear regression were calculated to give information on the relative importance of the association between each SF-36 dimensions and cost of ambulatory care. Of 4796 individuals appropriately surveyed, 221 (4.8%) reported OP. The control group included 651 individuals. The OP group experienced impaired HR-QOL compared to their matched counterparts, all the difference in mean or median SF-36 scores being significant at the level of P < 0.001. Osteoporotic respondents averaged 816 in cost of ambulatory care whereas controls averaged 579 (P < 0.001). When looking at detailed comparisons between categories of cost, costs in the OP group far exceeded those in the control group, all the differences being significant at the level of P < 0.001 except for home health nurse (P = 0.012). In the OP group, vitality dimensions played the most important role in the determination of cost (beta = -0.28, P < 0.001), followed by physical functioning (beta = -0.26, P < 0.01), general health, and social functioning (beta = -0.23, P < 0.01). This study evidences the burden of OP in terms of HR-QOL and cost of ambulatory care. Exploring the association between HR-QOL and cost show that mental dimension such as vitality can play an important role in the determination of cost. Conclusively, they should not be neglected in future management of OP

Development and assessment of the Osteoporosis Index of Risk (OSIRIS) to facilitate selection of women for bone densitometry

A simple questionnaire would be useful to identify individuals most in need of bone mineral density (BMD) testing. We designed a new predictive model and risk assessment instrument based on an extensive review of the literature evaluating risk factors for osteoporosis, and tested its performance in a large cohort of postmenopausal women in whom BMD was measured by dual x-ray absorptiometry. In total, 1303 postmenopausal women from an outpatient osteoporosis clinic participated in this study. The Osteoporosis Index of Risk (OSIRIS) is based on four variables: age, body weight, current hormone replacement therapy use and history of previous low impact fracture. The sensitivity and specificity for an OSIRIS value of +1 were respectively 78.5% and 51.4%. The AUC under the ROC curve of OSIRIS was 0.71. Three categories were arbitrarily created using OSIRIS, with cutoff of +1 and -3. The low risk category (OSIRIS > +1) represented 41% of all women; only 7% of the women in this category had osteoporosis. The prevalence of osteoporosis was very high (66%) among the group at high risk (OSIRIS < -3 representing 15% of all women). The prevalence of osteoporosis was 39% in the intermediate risk group (-3 < OSIRIS < +1, 44% of all women). In conclusion, OSIRIS is a simple index based on four easy-to-collect variables from postmenopausal women, it shows a high degree of accuracy, and performed well for classifying the degree of risk of osteoporosis in western European women of Caucasian lineage. Based on this instrument it is possible to propose a strategy that would initiate treatment in women with very high risk, postpone BMD measurement in women with low risk and limit BMD measurement to women with intermediate risk of osteoporosis, this would spare more than 55% of the densitometry bill compared with a mass screening scenario

Intensive and Prolonged Health Promotion Strategy May Increase Awareness of Osteoporosis among Postmenopausal Women

The aim of the study was to measure the results of a 15-year health promotion strategy towards osteoporosis, in an urban community of subjects over 45 years old, in terms of osteoporosis awareness and handling. To this end an ancillary study to a large survey of the Belgian population's self-perceived health status was carried out. A rectangular sample of 4800 individuals over 45 years old was randomly selected in two Belgian cities, among the affiliates of the two main health insurance providers. One of the cities (Liege) had been, since the early 1980s, the target of a constant health promotion strategy, directed to both the medical community and the general population, aimed at increasing osteoporosis awareness in women after the menopause. During the same period, no particular steps were taken in the other city (Aalst) to increase osteoporosis awareness in the community. In our study, the participants were asked to spontaneously report any chronic, serious and/or severe disorders that they had been suffering from, for at least 6 months, during the previous 12 months. They also provided a list of drugs they were taking at the time of the survey. Osteoporosis was reported to be a disease affecting 1.5% of men in Aalst and 1.3% of men in Liege (p = 0.61). For women, osteoporosis was reported to be present in 4.8% in Aalst and 10.8% in Liege (p<0.001). Self-reporting of osteoporosis prevalence in Liege was statistically significantly higher in women aged 45-64 years, 65-74 years or over 75 years (p<0.001). Obesity, alcohol consumption or physical activity were equally distributed between women from Liege and Aalst. Prescription drugs used for osteoporosis had been delivered to a similar proportion of men in Aalst and Liege. In women, a statistically significant difference in these prescription drugs was observed between Liege and Aalst, both for the overall population (p<0.001) and in each of the age classes (p<0.001 for 45-64 years and 65-74 years; p<0.009 for over 75 years). A continuous long-term health promotion strategy, directed toward both physicians and the general population, thus appears to increase awareness about osteoporosis in women over 45 years and/or in the medical community. This is reflected by an increase in self-reported prevalence of osteoporosis and in the prescription of drugs aimed at prevention and treatment of this disorder. Whether these observations reflect an appropriate diagnosis and a proper handling of the disease remains to be evaluated by objective diagnostic tools such as bone densitometry and by an evaluation of the effectiveness of prescription practices in postmenopausal women

Synthesis of 3-[(2-amino-1,2-dicyanovinyl)amino]-2-(benzoylamino)propenoates

Synthesis of 3-(2-amino-1,2-dicyanovinyl)amino-2-(benzoylamino)propenoate

A simple tool to identify asian women at increased risk of osteoporosis.

Patients with low bone mineral density (BMD) have a high risk of future fractures, and should be actively considered for treatment to reduce their risk. However, BMD measurements are not widely available in some communities, because of cost and lack of equipment. Simple questionnaires have been designed to help target high-risk women for BMD measurements, thereby avoiding the cost of measuring women at low risk. However, such tools have previously focused on evaluation of non-Asian women. We collected information about numerous risk factors from postmenopausal Asian women in eight countries in Asia using questionnaires, and evaluated the ability of these risk factors to identify women with osteoporosis as defined by femoral neck BMD T-scores < or =-2.5. Multiple variable regression analysis and item reduction yielded a final tool based on only age and body weight. This risk index had a sensitivity of 91% and specificity of 45%, with an area under the curve of 0.79. Previously published risk indices based on larger numbers of variables performed similarly well in this Asian population. Large differences in risk were identified using our index to create three categories: 61% of the high-risk women had osteoporosis, compared with only 15% and 3% of the intermediate- and low-risk women, respectively. The low-risk group represented 40% of all women, for whom BMD measurements are probably not needed unless important risk factors, such as prior nonviolent fracture or corticosteroid use, are present. An existing population-based sample of postmenopausal Japanese women was used to validate our index. In this sample of Japanese women the sensitivity was 98% and specificity was 29%; the low-risk category, for whom BMD is probably unnecessary, represented 25% of all women. We conclude that our index performed well for classifying the risk of osteoporosis among postmenopausal Asian women and applying it would result in more prudent use of BMD technology

Background for studies on the treatment of male osteoporosis: state of the art

Male osteoporosis represents an important, although long underestimated, public health problem. Both in men and in women aging is accompanied by continuous bone loss and by an exponential increase in the incidence of osteoporotic fracture, with a female to male incidence ratio of about 2 to 3 to 1 in the elderly for hip and vertebral fractures. Morbidity after osteoporotic fractures appears to be more serious and mortality more common in men than in women. To date, no single treatment has been proved to be effective and safe in published prospective studies.
  The present report, based on a systematic search of the literature on male osteoporosis, summarises the state of the art on the clinical consequences of male osteoporosis and its risk factors, in relation to the present state of knowledge about female osteoporosis. This constitutes the background for the design of rational clinical development strategies for therapeutic interventions in male osteoporosis. From this review of the literature it is apparent that notwithstanding the existing sex differences in pathophysiology of osteoporosis and the difference in age-specific incidence of osteoporotic fractures, there are also important similarities between osteoporosis in women and men. The higher incidence of fracture in women than in men results from quantitative differences in risk factors rather than from different risk factors. Even though there are sex differences in bone geometry, incidence of fracture seems to be similar in men and women for a same absolute areal bone mineral density. However, the lack of data on the changes in fracture rates in men resulting from pharmacological intervention, leading to changes in bone mineral density or bone turnover, remains the main limitation for extrapolation of established treatment outcomes from women to men.


Enhancing the luminescence yield of Cr 3+ in β -Ga 2 O 3 by proton irradiation

International audienceIn situ ion-beam-induced luminescence measurements reveal a strong enhancement of the Cr 3+ emission yield in electrically conductive chromium doped β-Ga 2 O 3 single crystals upon proton irradiation. The observed effect can be explained based on the Fermi-level pinning caused by radiation defects. This pinning of the Fermi level activates deep carrier traps that can act as sensitizers of the Cr 3+ emission. In agreement with this model, in semi-insulating samples, where the Fermi level lies deep in the bandgap, the Cr 3+ emission is present already in as-grown samples, and no enhancement of its intensity is observed upon proton irradiation. The boost of the Cr 3+ emission yield by irradiation, observed in conductive samples, is reversed by thermal annealing in argon at temperatures above 550 °C for 30 s. The results reveal a high potential of Cr-doped β-Ga 2 O 3 for in situ and ex situ optical radiation detection and dosimetry