262 research outputs found
Natural Killer cells responsiveness to physical esercise: a brief review
Natural killer cells (NK) are a group of peripheral blood lymphocytes which display cytotoxic ac- tivity against a wide range of tumour cells. They are a consistent part of the inflammatory re- sponse that is activated when either internal or external injuries occur as they are able to syn- thesize perforins. An important role is played by NK cells in the host defence against tumours without expressing any antigen-binding recap- tor in their membrane which, however, distin- guish T and B lymphocytes. NK activity appears early in the immune response, thus providing immediate protection during the time required for the activation and proliferation of cytotoxic T lymphocytes and for their differentiation into functional cells. Even though much research regarding the effects of aerobic training exercise on NK cell numbers and function, there appears to be much controversy regarding its effect. NK cells are rapidly mobilized into circulation in response to acute exercise, most likely by in- creased shear stress and catecholamine-in- duced down-regulation of adhesion molecule expression. However, tissue injury and inflam- mation which often accompanies strenuous ex- ercise have been associated to post-exercise NK cell suppression. Scientific evidence indicates exercise-induced changes in NK cell redistribu- tion and function should be strongly influenced by stress hormones including catecholamines, cortisol and prolactin as well as by soluble me- diators such as cytokines and prostaglandins. The role of exercise therapy in cancer patients and survivors rehabilitation is becoming increasingly important as it is thought to modulate immunity and inflammation. However, more knowledge about the effects of exercise on im-mune function in these patients is needed
Hydroxytyrosol but not resveratrol ingestion induced an acute increment of post exercise blood flow in brachial artery
The aim of this study was to test if previous ingestion of compounds containing resveratrol or hydroxytyrosol, followed by an exhausting hand grip exercise, could induce an acute post-exercise increase in brachial blood flow. Six healthy subjects (three males and three females, 35 ± 7 years), 60 minutes after ingestion of a capsule containing 200 mg of resveratrol or 30 ml of extra virgin olive oil enriched with tyrosol, oleuropein and hydroxytyrosol, performed a hand grip exercise equal to half of their maximum strength until they were no longer able to express the same force (2-day interval between tests). The nonparametric Wilcoxon signed rank test was used for statistical evaluations. Brachial artery blood flow (Fba) and both blood velocity (Vba) and artery diameter (Dba) were assessed immediately after exercise cessation by means of colour Doppler ultrasound. After ingestion of the oil mixture the post-exercise value of Fba median was 2.4 times higher than that after ingestion of the resveratrol compound (P = 0.03), and also the Vba median concerning the hydroxytyrosol was 1.9 times higher than that of the resveratrol (P = 0.03). Both functional foods did not lead to a significant difference in the Dba medians. These results indicate that hydroxytyrosol, but not resveratrol, may be an effective adjuvant of recreational or agonistic, long-lasting sports performances, thanks to the powerful blood flow increment which can be obtained as soon as one hour from its oral intake
Possible Assessment of Calf Venous Pump Efficiency by Computational Fluid Dynamics Approach
Three-dimensional simulations of peripheral, deep venous flow during muscular exercise in limbs of healthy subjects and in those with venous dysfunction were carried out by a computational fluid-dynamics (CFD) approach using the STAR CCM + platform. The aim was to assess the effects of valvular incompetence on the venous calf pump efficiency. The model idealizes the lower limb circulation by a single artery, a capillary bed represented by a porous region and a single vein. The focus is on a segment of the circuit which mimics a typical deep vein at the level of the calf muscle, such as the right posterior tibial vein. Valves are idealized as ball valves, and periodic muscle contractions are given by imposing time-dependent boundary conditions to the calf segment wall. Flow measurements were performed in two cross-sections downstream and upstream of the calf pump. Model results demonstrate a reduced venous return for incompetent valves during calf exercise. Two different degrees of valvular incompetence are considered, by restricting the motion of one or both valves. Model results showed that only the proximal valve is critical, with a 30% reduction of venous return during calf exercise in case of valvular incompetence: the net flow volume ejected by the calf in central direction was 0.14 mL per working cycle, against 0.2 mL for simulated healthy limbs. This finding appeared to be consistent with a 25% reduction of the calf ejection fraction, experimentally observed in chronic venous disease limbs compared with healthy limbs
Modulation of cardiac contractility by muscle metaboreflex following efforts of different intensities in humans.
Mechatronic face mask anti covid-19 to remotely record cardiorespiratory variables in farm’s workers engaged in jobs at high risk of infection
The most frequent prodromes of COVID-19 infection are fever, signs of respiratory diseases, cough and shortness of breath. Nevertheless, it is not infrequent that patients with COVID-19 also show cardiac symptoms. So, it is of importance to detect the prodromal symptoms of the COVID-19 infection in order to be able to make a diagnosis as quickly as possible to provide the immediate insertion of the infected people in isolation/therapy protocols. Here is presented a prototype of a smart face mask, named AG47-SmartMask that, in addition to the function of both an active and passive anti COVID-19 filter by an electro-heated filter brought to a minimum temperature of 38°C, it also allows the continuous monitoring of numerous cardio-pulmonary variables. Several specific sensors are incorporated into the mask to assess the inside mask temperature from which synchronous waving with the breathing was acquired the breath frequency, relative humidity, air pressure together and end tidal carbon dioxide percentage, and an auricular assessment of the body temperature, the heart rate and the percentage of oxygen saturation of haemoglobin. Sensors are embedded within an advanced ICT platform. To validate the AG47-SmartMask tool, were engaged twenty seven Farm’s workers of a vegetable packaging chain and they dressed the face mask device to simulate, while working, both tachypnea and cough, and the AG47-SmartMask faithfully quantified the simulated dyspnoic events
Assessing simulated arm lymphoedema by a prototype of bioimpedance spectroscopy device. Possible implication of its use in the follow up of patients who underwent extensive breast cancer surgery
The aim of this research was to enable women after breast cancer surgery, in which arms lymphoedema often occurs, to self-monitor this disease using in-home an easy-to-use-device which assesses the arm’s resistance ratio, considered an indirect, non-invasive index of increased extracellular water volume in those limbs. An homemade equipment based on the bioimpedance spectroscopy technique, was tested on 20 healthy volunteers which, by means of two ECG disposable electrodes, connected to the device both their dominant and auxiliary upper arms and changes in electrical resistance were assessed while an alternate current of low intensity and sweeping frequency from 15 to 75 kHz had be injected. In the same volunteers, an arm lymphoedema with about 100 ml excess of extracellular water was simulated by subtracting 0.8% from measured resistance values in each arm. The arms’ resistance ratio against the increasing frequency gave rise to a parabolic branch visible on a mobile phone screen and, when the arm lymphoedema was simulated, the corresponding curve appeared positioned below that of the one without oedema. The patient’s self-awareness, due to the device’s self-management, could allow these subjects to actively approach the disease while sharing their results remotely with clinical specialists by an internet connection
Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129
We present new observations of the galaxy cluster 3C 129 obtained with the
Sardinia Radio Telescope in the frequency range 6000-7200 MHz, with the aim to
image the large-angular-scale emission at high-frequency of the radio sources
located in this cluster of galaxies. The data were acquired using the
recently-commissioned ROACH2-based backend to produce full-Stokes image cubes
of an area of 1 deg x 1 deg centered on the radio source 3C 129. We modeled and
deconvolved the telescope beam pattern from the data. We also measured the
instrumental polarization beam patterns to correct the polarization images for
off-axis instrumental polarization. Total intensity images at an angular
resolution of 2.9 arcmin were obtained for the tailed radio galaxy 3C 129 and
for 13 more sources in the field, including 3C 129.1 at the galaxy cluster
center. These data were used, in combination with literature data at lower
frequencies, to derive the variation of the synchrotron spectrum of 3C 129
along the tail of the radio source. If the magnetic field is at the
equipartition value, we showed that the lifetimes of radiating electrons result
in a radiative age for 3C 129 of t_syn = 267 +/- 26 Myrs. Assuming a linear
projected length of 488 kpc for the tail, we deduced that 3C 129 is moving
supersonically with a Mach number of M=v_gal/c_s=1.47. Linearly polarized
emission was clearly detected for both 3C 129 and 3C 129.1. The linear
polarization measured for 3C 129 reaches levels as high as 70% in the faintest
region of the source where the magnetic field is aligned with the direction of
the tail.Comment: 19 pages, 17 figures, accepted for publication in MNRA
Imaging of the solar atmosphere in the centimetre-millimetre band through single-dish observations
Solar observations offer both a rich interdisciplinary laboratory on fundamental astrophysics and precious tools for Space Weather applications. The involved plasma processes determine a complex radio emission picture that could be efficiently explored through single-dish imaging at high frequencies. In particular, mapping the brightness temperature of the free-free radio emission in the centimetre and millimetre range is an effective tool to characterise the vertical structure of the solar atmosphere. We are performing continuum imaging of the solar chromosphere in K-band (18-26.5 GHz, spatial resolution ∼1 arcmin) with the 32-m diameter Medicina radio telescope and with the 64-m diameter Sardinia Radio Telescope (SRT), as a first scientific demonstration test for the potentialities of Italian single-dish antennas in this field. This will also be useful for the assessment of observation parameters aiming at studying in detail the chromospheric brightness temperature of the quiet Sun, the solar flares, active regions and the sunspots, at high radio frequencies. These early observations proved that our antennas and Kband receivers are stable during solar pointing and could provide full mapping of the solar disk in ∼1 hour exposure using state-of-the-art imaging techniques
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