Remarks on the behaviour of financial market efficiency during the COVID-19 pandemic. The case of VIX.

This paper investigates the Chicago Board Option Exchange Volatility Index's ('VIX') response to the COVID-19 pandemic crisis, in terms of information efficiency. First, we estimate an Efficiency Index over rolling windows, based on closing levels, for a period between 1995-01-03 and 2020-12-30. Second, we check for the presence of deterministic chaos in efficiency series, by using the largest Lyapunov exponent and sample, as well as permutation entropy. However, we do not find that these estimators provide a clear evidence of a substantial change in VIX's efficiency during 2020, in terms of deterministic chaos and irregular dynamics.

Indications and efficiency of dapsone in IgA vasculitis (Henoch-Schonlein purpura): case series and a review of the literature.

Immunoglobulin A (IgA) vasculitis (Henoch-Schonlein purpura (HSP)) is the most common vasculitis in children. It is characterized by purpuric rash, arthritis, gastrointestinal, and/or renal involvement. Spontaneous resolution is the typical outcome. In chronic cutaneous manifestations of IgA vasculitis, dapsone seems to show a good effectiveness. Multiple case reports and case series about dapsone in chronic IgA vasculitis are available. However, no clear evaluation of its indications, its effectiveness, or its usage guidelines (optimal dosage or duration of treatment) is available. We reviewed the published cases of IgA vasculitis treated by dapsone and compared them with 2 similar cases that we encountered. Seventeen patients (ranging from 22 months old to 16 years old) with severe or persistent clinical signs of IgA vasculitis were included. Dapsone showed good results on the resolution of cutaneous lesions but not on renal manifestations. Complications (methemoglobinemia) were observed on 1 patient. Half of the patients relapsed after treatment discontinuation. The difference between the time lapse before initiation and the duration of the treatment was not significant.Conclusion: We suggest that dapsone can have a positive effect in chronic IgA vasculitis when cutaneous manifestations last more than 6 weeks at the dosage of 1-2 mg/kg once per day during 1 week. What is Known: • IgA vasculitis or Henoch-Schonlein purpura is the most common vasculitis in children and affects mostly small vessels of the skin, kidney, and gastrointestinal tract. It resolves spontaneously in most of the cases. Exceptionally, cutaneous lesions can last several weeks. • Dapsone is a bacteriostatic antibacterial sulfonamide drug found to be effective in the treatment of some inflammatory dermatological diseases like IgA vasculitis. What is New: • Dapsone is effective against chronic purpuric lesion (> 6 weeks) at the minimal dose of 1 mg/kg/day. • Relapse occurs frequently after discontinuation but responds after a second course of treatment. A longer duration of treatment or a delay in treatment by dapsone does not seem to influence the relapse rate.

Destruction of the flame retardant hexabromocyclododecane in a full-scale municipal solid waste incinerator.

Hexabromocyclododecane containing polystyrene foam obtained from the building and construction market has been co-incinerated in a full-scale waste incineration plant. The co-feeding of 1 and 2 wt% of polystyrene foam had no influence on the operation of the plant. The bromine content increased the raw gas hydrogen bromide concentration slightly. The air emission, including that of dioxins and bromine, was not altered and so was the quality of the solid residues. The hexabromocyclododecane concentrations in the solid residues were almost identical, regardless of whether or not and how much polystyrene foam was added. The obtained destruction efficiency was >99.999% independent of the amount of added polystyrene foam. This finding indicates a virtually total destruction of hexabromocyclododecane.

Cutaneous Melanoma and Glioblastoma Multiforme Association-Case Presentation and Literature Review.

The occurrence of both melanoma and glioma was first suggested by the observation of a familial association between these conditions, which was later confirmed by the description of the melanoma-astrocytoma syndrome, an extremely rare, inherited affliction in which people have an increased risk of developing melanoma and nervous system tumors. Taking into consideration the common embryologic precursor, the neuroectoderm, it was hypothesized that this syndrome is associated with a genetic disorder. While some families with germline CDKN2A mutations are prone to develop just melanomas, others develop both melanomas and astrocytomas or even other nervous-system neoplasms. Herein, we report the case of a 63-year-old male patient with no personal or family history of malignancy who had primary melanoma followed by glioblastoma. Our case report suggests that the occurrence of both melanoma and glioblastoma is most likely not coincidental but instead linked to genetic mutations of common embryologic precursors or signaling pathways.

Poly(vinyl alcohol boric acid)-Diclofenac Sodium Salt Drug Delivery Systems: Experimental and Theoretical Studies.

The main aim of the paper was to simulate the drug release by a multifractal theoretical model, as a valuable method to assess the drug release mechanism. To do this, drug delivery films were prepared by mixing poly(vinyl alcohol boric acid) (PVAB) and diclofenac (DCF) sodium salt drug in different mass ratios from 90/10 to 70/30, in order to obtain drug delivery systems with different releasing rates. The different drug content of the three systems was confirmed by energy-dispersive spectroscopy (EDAX) analysis, and the encapsulation particularities were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), and polarized optical microscopy (POM) techniques. The ability of the PVAB matrix to anchor the DCF was assessed by Fourier transform infrared (FTIR) spectroscopy. The in vitro release of the diclofenac sodium salt from the formulations was investigated in biomimetic conditions (pH = 7.4 and 37°C) by UV-Vis spectroscopy, measuring the absorbance of the drug at 275 nm and fitting the results on a previously drawn calibration curve. An estimation of the drug release kinetics was performed by fitting three traditional mathematical models on experimental release data. Further, the drug delivery was simulated by the fractal theory of motion, in which the release dynamics of the polymer-drug complex system is described through various Riccati-type "regimes." To explain such dynamics involved multifractal self-modulation in the form of period doubling, quasiperiodicity, intermittency, etc., as well as multifractal self-modulation of network type. Standard release dynamics were explained by multifractal behaviors of temporary kink type. The good correlation between the traditional mathematical models and the new proposed theoretical model demonstrated the validity of the multifractal model for the investigation of the drug release.

Nanomaterials for Wound Healing and Infection Control.

Wound healing has been intensely studied in order to develop an "ideal" technique that achieves expeditious recovery and reduces scarring to the minimum, thus ensuring function preservation. The classic approach to wound management is represented by topical treatments, such as antibacterial or colloidal agents, in order to prevent infection and promote a proper wound-healing process. Nanotechnology studies submicroscopic particles (maximum diameter of 100 nm), as well as correlated phenomena. Metal nanoparticles (e.g., silver, gold, zinc) are increasingly being used in dermatology, due to their beneficial effect on accelerating wound healing, as well as treating and preventing bacterial infections. Other benefits include: ease of use, less frequent dressing changes and a constantly moist wound environment. This review highlights recent findings regarding nanoparticle application in wound management.