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Cold therapy is commonly used as a procedure to relieve pain symptoms, particularly in inflammatory diseases, injuries and overuse symptoms. A peculiar form of cold therapy (or stimulation) was proposed 30 years ago for the treatment of rheumatic diseases. The therapy, called whole-body cryotherapy (WBC), consists of exposure to very cold air that is maintained at -110 degrees C to -140 degrees C in special temperature-controlled cryochambers, generally for 2 minutes. WBC is used to relieve pain and inflammatory symptoms caused by numerous disorders, particularly those associated with rheumatic conditions, and is recommended for the treatment of arthritis, fibromyalgia and ankylosing spondylitis. In sports medicine, WBC has gained wider acceptance as a method to improve recovery from muscle injury. Unfortunately, there are few papers concerning the application of the treatment on athletes. The study of possible enhancement of recovery from injuries and possible modification of physiological parameters, taking into consideration the limits imposed by antidoping rules, is crucial for athletes and sports physicians for judging the real benefits and/or limits of WBC. According to the available literature, WBC is not harmful or detrimental in healthy subjects. The treatment does not enhance bone marrow production and could reduce the sport-induced haemolysis. WBC induces oxidative stress, but at a low level. Repeated treatments are apparently not able to induce cumulative effects; on the contrary, adaptive changes on antioxidant status are elicited--the adaptation is evident where WBC precedes or accompanies intense training. WBC is not characterized by modifications of immunological markers and leukocytes, and it seems to not be harmful to the immunological system. The WBC effect is probably linked to the modifications of immunological molecules having paracrine effects, and not to systemic immunological functions. In fact, there is an increase in anti-inflammatory cytokine interleukin (IL)-10, and a decrease in proinflammatory cytokine IL-2 and chemokine IL-8. Moreover, the decrease in intercellular adhesion molecule-1 supported the anti-inflammatory response. Lysosomal membranes are stabilized by WBC, reducing potential negative effects on proteins of lysosomal enzymes. The cold stimulation shows positive effects on the muscular enzymes creatine kinase and lactate dehydrogenase, and it should be considered a procedure that facilitates athletes' recovery. Cardiac markers troponin I and high-sensitivity C-reactive protein, parameters linked to damage and necrosis of cardiac muscular tissue, but also to tissue repair, were unchanged, demonstrating that there was no damage, even minimal, in the heart during the treatment. N-Terminal pro B-type natriuretic peptide (NT-proBNP), a parameter linked to heart failure and ventricular power decrease, showed an increase, due to cold stress. However, the NT-proBNP concentrations observed after WBC were lower than those measured after a heavy training session, suggesting that the...

We show that shot noise in a resonant-tunneling diode biased in the negative differential resistance regions of the I-V characteristic is enhanced with respect to "full" shot noise. We provide experimental results showing a Fano factor of up to 6.6, and show that it is a dramatic effect caused by electronelectron interaction through the Coulomb force, enhanced by the particular shape of the density of states in the well. We also present numerical results from the proposed theory, which are in agreement with the experiment, demonstrating that the model accounts for physics relevant to the phenomenon.[S0031-9007(97)05143-0] PACS numbers: 73.40.Gk, 72.70. + m, 73.20.Dx Deviations from the purely poissonian shot noise (the so-called "full" shot noise) in mesoscopic devices and resonant tunneling structures have been the subject of growing interest in the last decade [1][2][3][4][5][6][7][8][9][10][11]. The main reason is that noise is a very sensitive probe of electron-electron interaction [12], because of both the Pauli principle and the Coulomb force, and provides information but obtainable from dc and ac characterization; furthermore, noise depends strongly on the details of device structure, so that the capability of modeling it in nanoscale devices implies and requires a deep understanding of the collective transport mechanisms of electrons.Almost all published theoretical and experimental studies have focused on the suppression of shot noise due to negative correlation between current pulses caused by single electrons traversing the device. Such correlation may be introduced by Pauli exclusion, which limits the density of electrons in phase space, and/or by Coulomb repulsion, depending on the details of the structure and on the dominant transport mechanism [6-8], and make the pulse distribution subpoissonian, leading to suppressed shot noise.In particular, for the case of resonant tunneling structures, several theoretical and experimental studies have appeared in the literature [2][3][4][5][6][7][8][9][10][11], assessing that the power spectral density of the noise current S in such devices may be suppressed down to half the "full" shot noise value S full 2qI, i.e., that associated with a purely poissonian process.In this Letter, we propose a theoretical model and show experimental evidence of the opposite behavior, that is, of enhanced shot noise with respect to S full , which is to be expected in resonant tunneling structures biased in the negative differential resistance region of the I-V characteristic. An attempt to model such phenomenon has been presented in Ref. [13].We shall show that in such a condition Coulomb interaction and the shape of the density of states in the well introduce positive correlation between consecutive current pulses, leading to a superpoissonian pulse distribution, which implies a superpoissonian shot noise.First, we shall show an intuitive physical picture of the phenomenon, then we shall express it in terms of a model for transport and noise in generic resonant tunneling stru...

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