12,189 research outputs found
Daylight saving time, circadian rhythms, and cardiovascular health
No full textVery recently, the European Parliament, called to decide on possible abolition of the Daylight Saving Time (DST), approved a resolution calling the scientific community to conduct a more in-depth evaluation. The question is based on disruption of body's circadian rhythms. We review here the relationship between DST and cardiovascular health. The available evidence suggests the existence of an association between DST and a modest increase of occurrence of acute myocardial infarction, especially in the first week after the spring shift. Possible mechanisms include sleep deprivation, circadian misalignment and environmental conditions. The role of gender and individual preference in circadian rhythms (chronotype) will need further assessment
Aortic coartaction in the elderly: how many errors lie behind an unexpected diagnosis?
No full textA65-year-old woman was admitted to our department
because of chest pain and untreated hypertension. She had
been well until 6 years previously when a diagnosis of
hypertension was made. She reported poor control of blood
pressure associated with leg weakness in coincidence with
tentatively aggressive anti-hypertensive therapy. Aclinical diagnosis of aortic coarctation was made
[1], and a spiral TC study revealed a stenosis of the aorta
2 cm below the origin of the subclavia; a 2 cm aneurysm was present in the proximity of
the stenosis (Fig. 1, white arrow) and epiaortic arteries
were dilated
Please, Sir, pull down your socks!
No full textA 48-year-old male patient presented at the regular followupvisit seven months after a successful kidney transplant.After discussion of blood chemistries with the doctor, thepatient underwent a physical examination. As usual, heunbuttoned his shirt and undid his trouser belt. Inspectionof the limbs, after pulling up his trousers, confirmed thepresence of ankle oedema; the graft was quite firm, with nomurmurs in the area
Differential Influence of Physical Activity on Cardiopulmonary Performance and Stroke Volume Assessed at Cardiopulmonary Exercise Test in Pectus Excavatum: A Pilot Study
No full textBackground: Exercise training increases muscle VO2 by increasing O2 transport and O2 uptake while cardiac output increase might be limited by the conformation of the chest in subjects with pectus excavatum (PE). Aims: The aim of the present study was to investigate the influence of physical activity (PA) on functional parameters of cardiopulmonary performance and stroke volume obtained at Cardiopulmonary Exercise Test (CPET) in PE. Methods and Procedures: A cohort of adolescents (15 with PE and 15 age- and sex-matched healthy controls, HC) underwent Cardiopulmonary Exercise Test (CPET) and administration of the International Physical Activity Questionnaire – Short Form (IPAQ-SF) with estimation of weekly PA (METs h–1⋅week–1). Determinants of CPET parameters were investigated with multivariable linear regression analysis. Results: As expected, when compared to HC, PE had lower VO2 max (37.2 ± 6.6 vs. 45.4 ± 6.4 mL⋅kg–1⋅min–1, p < 0.05), and VO2/HR max (O2 pulse, 12.1 ± 2.4 vs. 16.2 ± 3.6 mL⋅min–1⋅bpm–1, p < 0.05). Importantly, physical activity level was a predictor of VO2 max (adjusted for sex, body mass index, FEV1%, and presence of PE, β = 0.085; 95% Cl 0.010 to 0.160, p = 0.029) whereas O2 pulse was independent from PA level (β = 0.035; 95% Cl −0.004 to 0.074). Conclusion: Physical activity is a determinant of VO2 max (cardiopulmonary performance), whereas it appears not to affect O2 pulse (a measure of stroke volume at peak exercise) related to constrained diastolic filling in PE
Miglioramento delle proprietà barriera di nanocompositi polimerici PET/PA per packaging alimentare
No full textCardioplegia and angiotensin II receptor antagonists modulate signal transducers and activators of transcription activation in neonatal rat myocytes.
No full textPrevious investigations have shown that the signal transducers and activators of transcription (STATs) signaling pathway play an important role in the modulation of apoptosis after ischemia and reperfusion. The mechanism for this enhanced cardioprotection is unknown, but we believe that alterations STATs may play a role. To investigate this hypothesis, we examined the effects of angiotension II type 1 (AT1) and angiotension II type 2 (AT2) receptor antagonist added to cardioplegia on the downstream response of different STATs, connected with proinflammatory pathways (STAT2, STAT5) and prohypertrophic and antiapoptotic pathways (STAT3). Isolated, nonworking hearts (n = 3 per group) from neonatal rats were perfused aerobically (4°C) for 20 min in the Langendorff mode with the modified St. Thomas' Hospital no. 2 (MSTH2) cardioplegic solution (Group 1), the MSTH2 cardioplegic solution + AT1 receptor antagonist (Group 2), and MSTH2 cardioplegic solution + AT2 receptor antagonist (Group 3). Thus, myocytes were isolated by enzymatic digestion, and STAT2, STAT3, and STAT5 were investigated in Western blot studies. Times to arrest after cardioplegia were 8-12 s for all groups. Total cardioplegia delivery volume was about 300 mL for the 20 min. Perfusion with the MSTH2 cardioplegic solution supplemented with AT1 receptor antagonist (Group 2) induced a significant reduction in STAT2 and STAT5 tyrosine phosphorylation (-58 and -63%, respectively, vs. Group 1, P < 0.05). Conversely, STAT2 and STAT5 activation were unaffected by perfusion with the MSTH2 cardioplegic solution supplemented with AT2 receptor antagonist (Group 3). The decreased activation of STAT2 and STAT5 observed in Group 2 was accompanied by reduction of interleukin-1β (-57% in Group 2 vs. Group 1, P < 0.05). There were no significant differences in STAT3 phosphorylation among all groups. Only the addition of AT1 receptor antagonist to MSTH2 cardioplegia significantly decreases the inflammatory response of the neonatal rat cardiomyocytes without affecting antiapoptotic influence provided by tyrosine phosphorylation of STAT3. AT1 receptor antagonist added to cardioplegia represents an additional modality for enhancing myocardial protection during cardiac surgery and could contribute to optimize the ischemia tolerance of the pediatric heart
PET/PA nanocomposite blends with improved gas barrier properties: effect of processing conditions
No full textThe aim of this research is to develop nanocomposite polyethylene terephthalate-polyamide blends (PET/MXD6 blends) with low oxygen permeability. Particular attention has been paid to the relation between barrier properties and the processing route adopted and therefore four different strategies were considered. Mechanical characterization shows that clay may effectively act as reinforcing filler in PET/MXD6 blends. Morphological characterization shows the strong effect of the processing strategy on clay dispersion and its distribution between the PET and polyamide phases. Barrier properties of PET/MXD6 nanocomposite blends are enhanced with respect to neat PET polymer as well as PET/MXD6 blends. The significant effect of processing techniques on barrier properties is also revealed
Price Systems for Random Amounts
No full textInternal consistency—or “coherence”—of a price system is the basis of several key concepts in many
fields, such as subjective probability (in Probability Theory), no-arbitrage pricing, and risk measures
(in Mathematical Finance). Furthermore, Actuarial Mathematics uses coherence to describe the analyti-
cal form of risk premia, and an analogous approach has recently been proposed for firms’ valuation.
Technically, it amounts to a characterisation of functionals with particular properties (a typical goal in
Functional Analysis), which translates into a numerical representation of preferences along the tradi-
tional guidelines of Decision Theory, whose analogies with Mathematical Finance are numerous and
really impressive. This is explored in this chapter
- …
