2,135 research outputs found
Implantation of silicon dioxide-based nanocrystalline hydroxyapatite and pure phase beta-tricalciumphosphate bone substitute granules in caprine muscle tissue does not induce new bone formation
No full textBackground: Osteoinductive bone substitutes are defined by their ability to induce new bone formation even at heterotopic implantation sites. The present study was designed to analyze the potential osteoinductivity of two different bone substitute materials in caprine muscle tissue.
Materials and methods: One gram each of either a porous beta-tricalcium phosphate (β-TCP) or an hydroxyapatite/silicon dioxide (HA/SiO2)-based nanocrystalline bone substitute material was implanted in several muscle pouches of goats. The biomaterials were explanted at 29, 91 and 181 days after implantation. Conventional histology and special histochemical stains were performed to detect osteoblast precursor cells as well as mineralized and unmineralized bone matrix.
Results: Both materials underwent cellular degradation in which tartrate-resistant acid phosphatase (TRAP)-positive osteoclast-like cells and TRAP-negative multinucleated giant cells were involved. The ß-TCP was completely resorbed within the observation period, whereas some granules of the HA-groups were still detectable after 180 days. Neither osteoblasts, osteoblast precursor cells nor extracellular bone matrix were found within the implantation bed of any of the analyzed biomaterials at any of the observed time points.
Conclusions: This study showed that ß-TCP underwent a faster degradation than the HA-based material. The lack of osteoinductivity for both materials might be due to their granular shape, as osteoinductivity in goat muscle has been mainly attributed to cylindrical or disc-shaped bone substitute materials. This hypothesis however requires further investigation to systematically analyze various materials with comparable characteristics in the same experimental setting
Effect of thermal loads on pre-cast concrete thermopile in Valencia, Spain
No full text[EN] The paper describes the thermo-mechanical behaviour of an experimental pre-cast driven pile, properly instrumented
and prepared to operate as a heat exchanger foundation element under the simultaneous action of mechanical and
thermal loads. Firstly, in situ static vertical load tests were carried out to analyse the pile mechanical behaviour.
Afterwards, two thermal tests were performed under constant mechanical load. The first thermal test was carried
out to characterise the pile¿ground system. By means of the second thermal test, the conditions of the pile in a
geothermal installation of an office building operating in cooling mode were simulated. The influence of the thermal
loads on the structural and geotechnical performance of the pile was subsequently analysed. Heating the pile leads
to increases in axial and end-bearing loads, changes in shear stresses distribution and reduction of factors of safety
for compressive ground resistance and for structural resistance of the pile.The authors thank the Spanish Ministry of Economy and Competitiveness for its financial support, through the programme INNPACTO 2011, for the design, installation and instrumentation of the geothermal pile in Valencia.Pardo, F.; De Santiago, C.; De Groot-Viana, M.; Urchueguía Schölzel, JF.; Arcos, JL.; Badenes Badenes, B. (2018). Effect of thermal loads on pre-cast concrete thermopile in Valencia, Spain. Environmental Geotechnics. https://doi.org/10.1680/jenge.17.00103
Dietary assessment methods for micronutrient intake in elderly people: a systematic review
No full textThe European micronutrient recommendations aligned (EURRECA) Network of Excellence seeks to establish clear guidelines for assessing the validity of reported micronutrient intakes among vulnerable population groups. A systematic literature review identified studies validating the methodology used in elderly people for measuring usual dietary micronutrient intake. The quality of each validation study selected was assessed using a EURRECA-developed scoring system. The validation studies were categorised according to whether the reference method applied reflected short-term intake ( <7 d), long-term intake ( = 7 d) or used biomarkers (BM). A correlation coefficient for each micronutrient was calculated from the mean of the correlation coefficients from each study weighted by the quality of the study. Thirty-three papers were selected, which included the validation of twenty-five different FFQ, six diet histories (DH), one 24-h recall (24HR) and a videotaped dietary assessment method. A total of five publications analysed BM, which were used to validate four FFQ, and one 24HR, presenting very good correlations only for vitamin E. The analysis of weighted correlation coefficients classified by FFQ or DH showed that most of the micronutrients had higher correlations when the DH was used as the dietary method. Comparing only FFQ results showed very good correlations for measuring short-term intakes of riboflavin and thiamin and long-term intakes of P and Mg. When frequency methods are used for assessing micronutrient intake, the inclusion of dietary supplements improves their reliability for most micronutrients
Corpo estranho de vias aéreas inferiores em crianças: análise de 234 casos
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de Pediatria
Fish fatty acids and mental health in older people
No full textBackground It has been suggested that the intake of fish and marine n-3 polyunsaturated fatty acids could protect against age-related cognitive decline and impaired mental well-being. However, results from observational studies are inconclusive and data from randomized controlled trials in older people without clinical dementia or depression are scarce. The objective of this thesis was to investigate the effect of daily supplementation with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on cognitive performance and mental well-being in an older non-clinical population. We also examined the effect of fish oil on gene expression profiles in white blood cells to identify early changes in pathways possibly related to mental health. Furthermore, we assessed the association of fish and EPA+DHA intake with mental health in different aging populations. Methods The effect of low and high doses of EPA+DHA (400 and 1,800 mg per day, respectively) on cognitive performance, several measures of mental well-being, and gene expression was examined in a 26-week randomized, double-blind, placebo-controlled trial. This study was conducted in 302 individuals aged 65 years or older with no clinical diagnosis of dementia or depression. Furthermore, the cross-sectional association between fatty fish and EPA+DHA intake with cognitive performance and the association with cognitive change during 6 years of follow-up was assessed in 1,025 aging US men who participated in the Veterans Affairs Normative Aging Study (NAS). In addition, the associations of EPA+DHA and fish intake with depressive symptoms and dispositional optimism were assessed in 644 free-living Dutch subjects with a history of myocardial infarction. Results Daily intake of low or high doses of EPA+DHA did not affect cognitive performance, mental well-being, anxiety, or quality of life, after 13 or 26 weeks of intervention. However, treatment with EPA+DHA for 26 weeks altered gene expression in white blood cells to a more anti-inflammatory and more anti-atherogenic profile. In elderly US men we found no association of fatty fish or EPA+DHA intake with cognitive performance or 6-year cognitive change. Intake of EPA+DHA was positively associated with dispositional optimism in subjects with a history of myocardial infarction. There was also a tendency for less depressive symptoms with a higher EPA+DHA or fish intake, but this association was no longer statistically significant after controlling for confounders. Conclusion Supplemental intake of EPA+DHA is unlikely to have a short-term impact on cognitive performance or mental well-being of older people without a clinical diagnosis of dementia or depression. Whether long-term intake of EPA+DHA and fish could be beneficial to the maintenance of cognitive performance or mental well-being of older people in Western populations still needs to be established. <br/
Prevalência de sintomas depressivos em pacientes diabéticos internados nas enfermarias de clínica médica da HU-UFSC
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de Clínica Médica
On the theory of beta-radioactivity IV : The polarization of beta-rays emitted by aligned nuclei in allowed transitions
No full textThe consequences of alignment of nuclei, which show allowed ß-transitions, are investigated. A general formula is derived for the transition probability of an allowed β-transition, in which the direction of emission of electron and neutrino, the polarization of the electron and the orientation of the nuclear spin are taken into account. The calculations have been made for a Hamiltonian for the β-interaction, which is an arbitrary "mixture" of the five invariants of the Dirac theory. The influence of the nuclear charge has, however, been neglected. From this formula the following results are immediately obtained:
The angular distribution of the β-radiation remains spherically symmetric if the nuclei are aligned, so that the alignment cannot be detected in this way.
The emitted β-radiation is polarized and the degree of polarization follows from the general formula. If we take the special case that the interaction Hamiltonian is of the tensor or the axial vector type and if the β-rays are emitted perpendicular to the direction of the nuclear spin of completely aligned nuclei with nuclear spin ji, the degree of polarization is given by: a) 1/Eif ji = jf + 1, b) 1/E(ji + 1), if ji = jf,c)ji/E(ji + 1), if ji = ji - 1. (E is the relativistic energy of the electrons, E ≈ 1 for small kinetic energies; jf gives the spin of the final nucleus)
Validade do índice Charlson de comorbidade corrigido para idade na predição de mortalidade intra-hospitalar nas enfermarias de clínica médica HU-UFSC
No full textTrabalho de Conclusão de Curso - Universidade Federal de Santa Catarina. Curso de Medicina. Departamento de Pediatria
A reappraisal of the impact of dairy foods and milk fat on cardiovascular disease risk
No full textBackground This review provides a reappraisal of the potential effects of dairy foods, including dairy fats, on cardiovascular disease (CVD)/coronary heart disease (CHD) risk. Commodities and foods containing saturated fats are of particular focus as current public dietary recommendations are directed toward reducing the intake of saturated fats as a means to improve the overall health of the population. A conference of scientists from different perspectives of dietary fat and health was convened in order to consider the scientific basis for these recommendations. Aims This review and summary of the conference focus on four key areas related to the biology of dairy foods and fats and their potential impact on human health: (a) the effect of dairy foods on CVD in prospective cohort studies; (b) the impact of dairy fat on plasma lipid risk factors for CVD; (c) the effects of dairy fat on non-lipid risk factors for CVD; and (d) the role of dairy products as essential contributors of micronutrients in reference food patterns for the elderly. Conclusions Despite the contribution of dairy products to the saturated fatty acid composition of the diet, and given the diversity of dairy foods of widely differing composition, there is no clear evidence that dairy food consumption is consistently associated with a higher risk of CVD. Thus, recommendations to reduce dairy food consumption irrespective of the nature of the dairy product should be made with cautionJ. Bruce German, Robert A. Gibson, Ronald M. Krauss, Paul Nestel, Benoît Lamarche, Wija A. van Staveren, Jan M. Steijns, Lisette C. P. G. M. de Groot, Adam L. Lock and Frédéric Destaillat
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