282 research outputs found

    Usefulness of calcaneal quantitative ultrasound stiffness for the evaluation of bone health in HIV-1-infected subjects: Comparison with dual X-ray absorptiometry

    Get PDF
    Objectives: With the development of effective treatments and the resulting increase in life expectancy, bone mineral density (BMD) alteration has emerged as an important comorbidity in human immunodeficiency virus type-1 (HIV-1)-infected individuals. The potential contributors to the pathogenesis of osteopenia/osteoporosis include a higher prevalence of risk factors, combined antiretroviral therapy (cART)-exposure, HIV-1 itself and chronic immune activation/inflammation. Dual-energy X-ray absorptiometry (DXA) is the “gold standard” technique for assessing bone status in HIV-1 population. Methods: We conducted a cross-sectional study to investigate bone mineral status in a group of 158 HIV-1-infected subjects. The primary endpoint was the feasibility of calcaneal quantitative ultrasound (QUS) as a screening tool for BMD. All subjects were receiving stable cART and were virologically suppressed (HIV-RNA <37 copies/mL) from at least 12 months. Calcaneal QUS parameters were analyzed to obtain information on bone mass and microarchitecture. The results were compared with those obtained by DXA. Results: No correlations were found between DXA/QUS parameters and demographic or HIV-1-specific characteristics, also including cART strategies. In the univariate analyses BMD, QUS indexes, and Fracture Risk Assessment Tool scores conversely showed significant associations with one or more demographic or HIV-1-related variables. Moreover, a significant relationship between calcaneal quantitative ultrasound index/stiffness and femoral/lumbar BMD values from DXA was described. The multivariate analysis showed an independent association between calcaneal quantitative ultrasound index/stiffness and body mass index, higher CD4+T-cell numbers and low 25-OH D2/D3 vitamin D levels <10 ng/mL (P-values: 0.004, 0.016, and 0.015, respectively). Conclusion: As an alternative and/or integrative examination to DXA, calcaneal QUS could be proposed as a useful screening in HIV-1-infected patients for assessing bone health impairment. In fact, the results obtained confirm that calcaneal QUS may be useful for monitoring bone status, being a noninvasive and inexpensive technique, especially in those subjects with the classical traditional risk factors for bone damage that were observed earlier in HIV-1 population

    ExoMars Mission Analysis and Design - Launch, Cruise and Arrival Analyses

    Get PDF
    ExoMars is ESA s next mission to planet Mars. The probe is aimed for launch either in 2013 or in 2016. The project is currently undergoing Phase B1 studies under ESA management and Thales Alenia Space Italia project leadership. In that context, DEIMOS Space is responsible for the Mission Analysis and Design for the interplanetary and the entry, descent and landing (EDL) activities. The present mission baseline is based on an Ariane 5 or Proton M launch in 2013 of a spacecraft Composite bearing a Carrier Module (CM) and a Descent Module (DM). A back-up option is proposed in 2016. This paper presents the current status of the interplanetary mission design from launch up to the start of the EDL phase

    Architettura come Ars Combinatoria = Architecture as Ars Combinatoria

    Get PDF
    L\u2019architettura non rappresenta pi\uf9, oggi, il limite della sperimentazione e dell\u2019innovazione. E\u2019 un\u2019arte estremamente low-tech il cui campo di possibilit\ue0 \ue8 quello di scegliere e usare quello che gi\ue0 \ue8 stato fatto in passato. E\u2019 per questo che la principale abilit\ue0 di un progettista dovrebbe essere quella di ri-conoscere le forme della complessit\ue0 all\u2019intorno: sono le citt\ue0 ad essere il pi\uf9 ampio palinsesto delle possibilit\ue0 dell\u2019architettura, nel rapporto biunivoco che si instaura tra una citt\ue0 che prende forma da un\u2019architettura e un\u2019architettura che ha le sue ragioni nella coeva citt\ue0. L\u2019architettura ha cos\uec il suo fondamento nell\u2019ospitalit\ue0, elemento che la distingue nettamente dal design

    Recent Advances in the Treatment of Neurodegenerative Diseases Based on GSH Delivery Systems

    Get PDF
    Neurodegenerative diseases, such as Parkinson's disease (PD) and Alzheimer's disease(AD), are a group of pathologies characterized by a progressive and specific loss of certain brain cell populations. Oxidative stress, mitochondrial dysfunction, and apoptosis play interrelated roles in these disorders. It is well documented that free radical oxidative damage, particularly on neuronal lipids, proteins, DNA, and RNA, is extensive in PD and AD brains. Moreover, alterations of glutathione (GSH) metabolism in brain have been implicated in oxidative stress and neurodegenerative diseases. As a consequence, the reduced GSH levels observed in these pathologies have stimulated a number of researchers to find new potential approaches for maintaining or restoring GSH levels. Unfortunately, GSH delivery to the central nervous system (CNS) is limited due to a poor stability and low bioavailability. Medicinal-chemistry- and technology-based approaches are commonly used to improve physicochemical, biopharmaceutical, and drug delivery properties of therapeutic agents. This paper will focus primarily on these approaches used in order to replenish intracellular GSH levels, which are reduced in neurodegenerative diseases. Here, we discuss the beneficial properties of these approaches and their potential implications for the future treatment of patients suffering from neurodegenerative diseases, and more specifically from PD and AD

    The Mediterranean Diet in the Prevention of Degenerative Chronic Diseases

    Get PDF
    Degenerative chronic diseases are a problem related to the aging phenomenon of industrialized countries due to the increase of risk factors and related comorbidity such as overweight, obesity, metabolic syndrome, diabetes, hypertension and hyperlipidemia with a consequent increased risk of cardiovascular disease (CVD) and cancer. Moreover, the significant reduction of physical activity in daily life and the huge growth in food availability have considerably increased the risk of such diseases. Particular attention should be paid to primary prevention by means of health strategies based on improvement in lifestyle intervention such as implementation of Mediterranean diet and promotion of physical activity programs. In this chapter, the protective effect of Mediterranean diet and the role of certain foods and/or their constituents are analyzed; the possible mechanisms by which Mediterranean diet is effective in the prevention of cardiovascular and other chronic diseases are presented, in particular the effects exerted by antioxidants, polyphenols, fibers, unsaturated fatty acids, and alcohol. The genetic revolution in the past decades has produced new fields of study where the interaction between foods, nutrients, and our genetic makeup is investigated. The relationship between nutrigenetics and nutrigenomics and the Mediterranean diet are the future area that research should discover

    Diuretic therapy in heart failure: current controversies and new approaches for fluid removal

    Get PDF
    Hospitalization for heart failure is a major health problem with high in-hospital and postdischarge mortality and morbidity. Non-potassium-sparing diuretics (NPSDs) still remain the cornerstone of therapy for fluid management in heart failure despite the lack of large randomized trials evaluating their safety and optimal dosing regimens in both the acute and chronic setting. Recent retrospective data suggest increased mortality and re-hospitalization rates in a wide spectrum of heart failure patients receiving NPSDs, particularly at high doses. Electrolyte abnormalities, hypotension, activation of neurohormones, and worsening renal function may all be responsible for the observed poor outcomes. Although NPSD will continue to be important agents to promptly resolve signs and symptoms of heart failure, alternative therapies such as vasopressine antagonists and adenosine blocking agents or techniques like veno-venous ultrafiltration have been developed in an effort to reduce NPSD exposure and minimize their side effects. Until other new agents become available, it is probably prudent to combine NPSD with aldosterone blocking agents that are known to improve outcomes. J Cardiovasc Med 11:563-570 (C) 2010 Italian Federation of Cardiology

    On the application of replica molding technology for the indirect measurement of surface and geometry of micromilled components

    Get PDF
    The evaluation of micromilled parts quality requires detailed assessments of both geometry and surface topography. However, in many cases, the reduced accessibility caused by the complex geometry of the part makes it impossible to perform direct measurements. This problem can be solved by adopting the replica molding technology. The method consists of obtaining a replica of the feature that is inaccessible for standard measurement devices and performing its indirect measurement. This paper examines the performance of a commercial replication media applied to the indirect measurement of micromilled components. Two specifically designed micromilled benchmark samples were used to assess the accuracy in replicating both surface texture and geometry. A 3D confocal microscope and a focus variation instrument were employed and the associated uncertainties were evaluated. The replication method proved to be suitable for characterizing micromilled surface texture even though an average overestimation in the nano-metric level of the Sa parameter was observed. On the other hand, the replicated geometry generally underestimated that of the master, often leading to a different measurement output considering the micrometric uncertainty

    Orthostatic hypotension in elderly: Do you measure orthostatic and clinostatic blood pressure?

    Get PDF
    In this article we highlighted the blood pressure management in elderly patients with orthostatic hypotension

    Ischemic preconditioning in the younger and aged heart

    Get PDF
    : Ischemic preconditioning is the effect of brief ischemic episodes which protect the heart from the following more prolonged ischemic episode. This mechanism is effective in younger but not in aged heart. The age-related reduction of ischemic preconditioning has been demonstrated in experimental models and in elderly patients. Preinfarction angina, a clinical equivalent of ischemic preconditioning, reduces mortality in adult but not in elderly patients with acute myocardial infarction. Physical activity or caloric restriction is partially capable to preserve the cardioprotective effect of ischemic preconditioning in the aging heart. More importantly, physical activity and caloric restriction in tandem action completely preserve the protective mechanism of ischemic preconditioning. Accordingly, the protective mechanism of preinfarction angina is preserved in elderly patients with a high grade of physical activity or a low body-mass index. Thus, both physical activity and caloric restriction are confirmed as powerful anti-aging interventions capable to restore age-dependent reduction of a critical endogenous protective mechanism such as ischemic preconditioning

    A graphical method for performance mapping of machines and milling tools

    Get PDF
    Optimal design of the machining setup in terms of installed machines, cutting tools and process parameters is of paramount importance for every manufacturing company. In most of the metal cutting companies, all choices related to machine eligibility and cutting parameters selection typically come from heuristic approaches and follow supplier indications or base on the skill of experienced machine operators. More advanced solutions, such as model-based and virtual approaches, are adopted less frequently mainly due to the lack of these techniques in grasping the underlying knowledge successfully. Aim of this work is to introduce a synthetic graphical representation of machining centers and cutting tools capabilities, to provide an accessible way to evaluate the feasibility and close-to-limit conditions of the cutting process. Taking inspiration from previous scientific works from the measurement engineering field, a set of 2D and 3D graphs are presented to map machine, tools and process capabilities, as well as their obtainable manufacturing performances and expectable tool life. This approach synthesizes the nominal data coming from different sources (catalogues, database, tool model geometries etc.) and the real cutting tools parameters used during the production phase. Some examples are provided to show the potential of this graphical evaluation in supporting process planning and decision-making and in formalizing the machining setup knowledge. Further developments are devoted to extend the method to other manufacturing processes, including hybrid processes. At the same time, an in-process data gathering software will be integrated for building a solid database that can be used by an autonomous multi-technological process selector, as well as by a pre-process condition advisor in an Industry 4.0 oriented way
    corecore