322,982 research outputs found
Lymph node involvement in axillary hidradenitis suppurativa: A clinical, ultrasonographic and bacteriological study conducted during radical surgery
No full textBackground: Hidradenitis suppurativa (HS) is an inflammatory and chronic-recurrent disease of the hair follicle. Its aetiopathogenesis is not completely known. Although bacterial colonization and superinfection are clinically relevant, lymph node involvement has rarely been studied. Objectives: In this pilot retrospective study, we evaluated the clinical and microbiological nodal involvement in patients with axillary hidradenitis suppurativa. Materials and methods: We retrospectively analyzed patients suffering from axillary hidradenitis suppurativa and referred to the Dermatology Unit of the Foundation Ca’ Granda Ospedale Maggiore Policlinico in Milan between October 2018 and November 2019. The sampling procedure took place during the surgical excision of lesions at the Operative Unit of Plastic and Reconstructive Surgery of Policlinico San Donato Hospital. Three types of sample were sent to microbiological analysis: exudate swab, axillary lymph node, fistula. Result: In total, we recruited 10 patients. Two of them underwent bilateral axillary surgery. Nine lymph nodes were analyzed. In one patient, bacterial culture in lymph nodes, skin lesions and fistulae matched. Conclusions: Unequivocable conclusions cannot be drawn due to the low number of patients. Further studies are necessary to confirm the preliminary results of our retrospective pilot study
Compartment syndrome of the forearm following an electromyographic assessment
No full textWe present a case of compartment syndrome after electromyographic study of the upper limbs. The cause was the unintentional punction and laceration of the ulnar artery while the electromyography was being performed
Relaxation to the asymptotic distribution of global errors due to round off
No full textWe propose an analysis of the effects introduced by finite accuracy and round-off
arithmetic on discrete dynamical systems. We investigate, from a statistical viewpoint and using
the tool of the decay of fidelity, the error of the numerical orbit with respect to the exact one. As a
model we consider a random perturbation of the exact orbit with an additive noise, for which exact
results can be obtained for some prototype maps. For regular anysocrounous maps the fidelity has
a power law decay, whereas the decay is exponential if a random perturbation is introduced. For
chaotic maps the decay is superexponential after an initial plateau and our method is suitable to
identify the reliability threshold of numerical results, i.e. a number of iterations below which global
errors can be ignored. The same behaviour is observed if a random perturbation is introduced
Uses of Polypodium leucotomos Extract in Oncodermatology
No full textThe effects of UV radiation on the skin and its damage mechanisms are well known. New modalities of exogenous photoprotection have been studied. It was demonstrated that Polypodium leucotomos extract acts as an antioxidant, photoprotectant, antimutagenic, anti-inflammatory, and immunoregulator. It is effective when taken orally and/or applied topically to support the prevention of skin cancers. It also has an important role in preventing photoaging. This review aims to report the mechanisms through which Polypodium leucotomos acts and to analyze its uses in oncodermatology with references to in vitro and in vivo studies. Additionally, alternative uses in non-neoplastic diseases, such as pigmentary disorders, photosensitivity, and atopic dermatitis, have been considered
Asymptotic distribution of global errors in the numerical computations of dynamical systems
No full textWe propose an analysis of the effects introduced by finite-accuracy and round-off arithmetic on numerical computations of discrete dynamical systems. Our method, which uses
the statistical tool of the decay of fidelity, computes the error by directly comparing the
numerical orbit with the exact one (or, more precisely, with another numerical orbit computed with a much higher accuracy). Furthermore, as a model of the effects of round-off
arithmetic on the map, we also consider a random perturbation of the exact orbit with
an additive noise, for which exact results can be obtained for some prototype maps. We
investigate the decay laws of fidelity and their relationship with the error probability distribution for regular and chaotic maps, for both additive and numerical noise. In particular,
for regular maps we find an exponential decay for additive noise, and a power-law decay
for numerical noise. For chaotic maps, numerical noise is equivalent to additive noise, and
our method is suitable for identifying a threshold for the reliability of numerical results, i.e.,
the number of iterations below which global errors can be ignored. This threshold grows
linearly with the number of bits used to represent real numbers
Analysis of Bank Leverage via Dynamical Systems and Deep Neural Networks
No full textWe consider a model of a simple financial system consisting of a leveraged investor that invests in a risky asset and manages risk by using value-at-risk (VaR). The VaR is estimated by using past data via an adaptive expectation scheme. We show that the leverage dynamics can be described by a dynamical system of slow-fast type associated with a unimodal map on [0,1] with an addi-tive heteroscedastic noise whose variance is related to the portfolio rebalancing frequency to target leverage. In absence of noise the model is purely deterministic and the parameter space splits into two regions: (i) a region with a globally attracting fixed point or a 2-cycle; (ii) a dynamical core region, where the map could exhibit chaotic behavior. Whenever the model is randomly perturbed, we prove the existence of a unique stationary density with bounded variation, the stochastic stability of the process, and the almost certain existence and continuity of the Lyapunov exponent for the stationary measure. We then use deep neural networks to estimate map parameters from a short time series. Using this method, we estimate the model in a large dataset of US commercial banks over the period 2001--2014. We find that the parameters of a substantial fraction of banks lie in the dynamical core, and their leverage time series are consistent with a chaotic behavior. We also present evidence that the time series of the leverage of large banks tend to exhibit chaoticity more frequently than those of small banks
Therapies for Chronic Spontaneous Urticaria: Present and Future Developments
No full textChronic spontaneous urticaria (CSU) is a complex dermatological condition characterized by recurrent wheals and/or angioedema lasting for more than six weeks, significantly impairing patients’ quality of life. According to European guidelines, the first step in treatment involves second-generation H1-antihistamines (sgAHs), which block peripheral H1 receptors to alleviate symptoms. In cases with inadequate responses, the dose of antihistamines can be increased by up to fourfold. If symptoms persist despite this adjustment, the next step involves the use of omalizumab, a monoclonal anti-IgE antibody, which has shown efficacy in the majority of cases. However, a subset of patients remains refractory, necessitating alternative treatments such as immunosuppressive agents like cyclosporine or azathioprine. To address these unmet needs, several new therapeutic targets are being explored. Among them, significant attention is being given to drugs that block Bruton’s tyrosine kinase (BTK), such as remibrutinib, which reduces mast cell activation. Therapies like dupilumab, which target the interleukin-4 (IL-4) and IL-13 pathways, are also under investigation. Additionally, molecules targeting the Mas-related G protein-coupled receptor X2 (MRGPRX2), and those inhibiting the tyrosine kinase receptor Kit, such as barzolvolimab, show promise in clinical studies. These emerging treatments offer new options for patients with difficult-to-treat CSU and have the potential to modify the natural course of the disease by targeting key immune pathways, helping to achieve longer-term remission. Further research is essential to better elucidate the pathophysiology of CSU and optimize treatment protocols to achieve long-term benefits in managing this condition. Altogether, the future of CSU treatments that target pathogenetic mechanisms seems promising
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