Stardust Pattern as Evolution of Pigmented Spitz Nevi During Childhood.

INTRODUCTION: Spitz nevi (SN) are benign melanocytic proliferations frequently occurring in children. Some pigmented SN with a starburst pattern evolve into the "stardust" one, which is characterized by a central, black to gray, hyperpigmented area and remnants of a brown network at the periphery. These dermoscopy changes are often the first alert to induce excision. OBJECTIVES: The aim of this study is to enlarge the case series of stardust SN in children, in order to increase confidence with this new dermoscopic pattern and reduce unnecessary excisions. METHODS: This retrospective observational study was conducted with SN cases received from IDS members. The inclusion criteria were: clinical and/or histopathologic diagnosis of Spitz naevus with starburst appearance in children <12 years old, availability of a dermoscopic image at baseline and after follow-up of at least 1 year, availability of patient data. The dermoscopic images and their changes over time were assessed by three evaluators in consensus. RESULTS: 38 SN were enrolled, with a median age of 7 years and a median FUP duration of 15,5 months. Comparing the evolution with time of FUP, no significant differences were found between growing and involuting lesions in terms of patient age and sex, location and palpability of lesions. CONCLUSIONS: The long follow-up reported in our study could really support the concept of benignity of changing SN. A conservative approach is acceptable for nevi showing the stardust pattern, because it may be considered a physiological evolution of pigmented Spitz nevus, and urgent surgeries could be avoided.

Vacuum and Electromagnetic Fields Treatment to Regenerate a Diffuse Mature Facial Scar Caused by Sulfuric Acid Assault.

Acid attacks are on the rise, and they cause extensive and deep burns, especially on the face. The treatments used to improve the aesthetic, functional and social impact of non-acid scars do not always prove useful for acid scars. This article reports the case of a woman with an extended, mature, acid facial scar, caused by sulfuric acid assault, treated with a recent new procedure that combines the application of vacuum and electromagnetic fields. Before and after the treatment, the aesthetic appearance, and motor function of the face and neck were evaluated, as well as the level of hydration, the amount of sebum, the elasticity, and the pH of the skin. The improvements highlighted after the treatment of the aesthetic and functional characteristics of the face and neck, and of the physical parameters of the skin seemed to indicate that this particular treatment induces tissue regeneration, even in the nerve component. However, it is evident that the rehabilitation pathways of facial wounds and scars must be personalized, and must include continuous psychological support for the patient.

Anharmonic Aspects in Vibrational Circular Dichroism Spectra from 900 to 9000 cm-1 for Methyloxirane and Methylthiirane.

Vibrational circular dichroism (VCD) spectra and the corresponding IR spectra of the chiral isomers of methyloxirane and of methylthiirane have been reinvestigated, both experimentally and theoretically, with particular attention to accounting for anharmonic corrections, as calculated by the GVPT2 approach. De novo recorded VCD spectra in the near IR (NIR) range regarding CH-stretching overtone transitions, together with the corresponding NIR absorption spectra, were also considered and accounted for, both with the GVPT2 and with the local mode approaches. Comparison of the two methods has permitted us to better describe the nature of active "anharmonic" modes in the two molecules and the role of mechanical and electrical anharmonicity in determining the intensities of VCD and IR/NIR data. Finally, two nonstandard IR/NIR regions have been investigated: the first one about ≈2000 cm-1, involving mostly two-quanta bending mode transitions, the second one between 7000 and 7500 cm-1 involving three-quanta transitions containing CH-stretching overtones and HCC/HCH bending modes.

A Facile One-Pot Approach to the Fabrication of Nanocellulose-Titanium Dioxide Nanocomposites with Promising Photocatalytic and Antimicrobial Activity.

The combination of cellulosic materials and metal oxide semiconductors can provide composites with superior functional properties compared to cellulose. By using nanocellulose derived from agricultural waste, we propose a one-pot and environmentally friendly approach to the synthesis of nanocellulose-TiO2 (NC-TiO2) nanocomposites with peculiar photocatalytic activity and antibacterial effects. The as-prepared NC-TiO2 composites were fully characterized by different techniques, such as X-ray diffraction (XRD), µ-Raman, Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS). The results showed that well crystalline anatase TiO2 nanoparticles of about 5-6 nm were obtained. The photocatalytic activity in particular was evaluated by using methyl orange (MO) solution as a target pollutant at different pH values. It was found that all the tested NC-TiO2 nanocomposites showed stable photocatalytic activity, even after consecutive photocatalytic runs. In addition, NCT nanocomposites with higher TiO2 content showed degradation efficiency of almost 99% towards MO after 180 min of UV illumination. Finally, NC-TiO2 nanocomposites also showed intriguing antimicrobial properties, demonstrating to be effective against Gram-positive (Staphylococcus aureus, Bacillus subtilis) with 20-25 mm of inhibition zone and Gram-negative bacteria (Escherichia coli, Pseudomonas aeuroginosa) with 21-24 mm of inhibition zone, and fungi (Candida albicans) with 9-10 mm of inhibition zone.

Long-term proactive management of psoriasis with calcipotriol and betamethasone dipropionate foam: an Italian consensus through a combined nominal group technique and Delphi approach.

BACKGROUND: Although long-term management of psoriasis is paramount, this approach is challenging in clinical practice. In the recent PSO-LONG trial, a fixed-dose combination of betamethasone dipropionate (BD) and calcipotriol (Cal) foam applied twice a week on non-consecutive days for 52 weeks (proactive treatment) reduced the risk of relapse. However, the role of Cal/BD foam in the long-term management of psoriasis needs further clarifications. The ProActive Management (PAM) program, a nationwide Italian project, aims at reaching a consensus on the role of proactive management of psoriasis. METHODS: A steering committee generated some statements through the nominal group technique (NGT). The statements were voted by an expert panel in an adapted Delphi voting process. RESULTS: Eighteen statements were proposed, and the majority of them (14/18) reached a consensus during the Delphi voting. The need to provide long-term proactive topical treatment to reduce the risk of relapse for the treatment of challenging diseases sites or in patients where phototherapy or systemic therapies are contraindicated/ineffective was widely recognized. A consensus was reached about the possibility to associate the proactive treatment with systemic and biological therapies, without the need for dose intensification, thus favoring a prolonged remission. Moreover, the proactive treatment was recognized as more effective than weekend therapy in increasing time free from relapses. Approaches to improve adherence, on the other hand, need further investigation. CONCLUSIONS: The inclusion in guidelines of a proactive strategy among the effective treatment options will be a fundamental step in the evolution of a mild-moderate psoriasis therapeutic approach.

Sublimation Study of Six 5-Substituted-1,10-Phenanthrolines by Knudsen Effusion Mass Loss and Solution Calorimetry.

The vapor pressures of six solid 5-X-1,10-phenanthrolines (where X = Cl, CH3, CN, OCH3, NH2, NO2) were determined in suitable temperature ranges by Knudsen Effusion Mass Loss (KEML). From the temperature dependencies of vapor pressure, the molar sublimation enthalpies, ΔcrgHm0(⟨T⟩), were calculated at the corresponding average ⟨T⟩ of the explored temperature ranges. Since to the best of our knowledge no thermochemical data seem to be available in the literature regarding these compounds, the ΔcrgHm0(⟨T⟩) values obtained by KEML experiments were adjusted to 298.15 K using a well known empirical procedure reported in the literature. The standard (p0 = 0.1 MPa) molar sublimation enthalpies, ΔcrgHm0(298.15 K), were compared with those determined using a recently proposed solution calorimetry approach, which was validated using a remarkable amount of thermochemical data of molecular compounds. For this purpose, solution enthalpies at infinite dilution of the studied 5-chloro and 5-methylphenantrolines in benzene were measured at 298.15 K. Good agreement was found between the values derived by the two different approaches, and final mean values of ΔcrgHm0(298.15 K) were recommended. Finally, the standard molar entropies and Gibbs energies of sublimation were also derived at T = 298.15 K. The volatilities of the six compounds were found to vary over a range of three orders of magnitude in the explored temperature range. The large difference in volatility was analyzed in the light of enthalpies and entropies of sublimation. The latter was tentatively put in relation to the rotational contribution of the substituent group on the phenanthroline unit.

Perforator-Based Flap Reconstruction after Melanoma Resection: Evaluation of Oncological, Aesthetic, and Functional Outcomes.

BACKGROUND: Evidence in literature about the best reconstructive approach after melanoma resection is controversial, with some authors advocating that tissue rearrangement flap techniques might hinder the early detection of local relapses. The aim of the present study is to evaluate oncological, aesthetic, and functional outcomes following melanoma reconstruction using pedicled perforator-based flaps. METHODS: The authors reviewed all patients affected by melanoma treated during a 6-year period. Demographic data, tumor characteristics, and operative variables were evaluated. Locoregional recurrence was assessed with clinical and radiological follow-up. One-year postoperatively patients rated on a 5-point Likert scale the aesthetic and functional outcomes of the procedure. Three blind observers examined preoperative and 1-year postoperative photographs and rated the aesthetic outcome of the reconstructive procedure. RESULTS: One-hundred sixty-five patients were treated with wide excision and delayed reconstruction, including pedicled perforator-based flaps in 70 patients (group A) and primary closure in 95 patients (group B). Mean Breslow thickness was 2.972 and 2.189 mm in group A and B, respectively. There was no statistically significant difference in locoregional recurrence (chi-squared test, p = 0.8333; Fisher's exact test, p > 0.9999) between the two groups. Group A reported a higher satisfaction with both the aesthetic (mean rating 4.390 in group A and 4.094 in group B) and functional (mean rating 4.732 in group A and 4.170 in group B) outcomes of the procedure, the latter being statistically significant (p = 0.0006). CONCLUSION: This series suggests that pedicled perforator-based flaps provide optimal aesthetic and functional outcomes in melanoma reconstruction without impairing the locoregional control of the disease.

Thermodynamic and Kinetic Aspects of Formamidinium Lead Iodide Thermal Decomposition.

We report the results of a multi-technique study on the thermodynamics and kinetics of formamidinium lead iodide (FAPI) thermal decomposition. Thermodynamics was investigated by means of Knudsen effusion techniques. Kinetics was studied either by temperature-controlled powder X-ray diffraction or by two isoconversional treatments of differential scanning calorimetry data. FAPI appears to be much more thermally stable compared to methylammonium lead iodide, as predictable from the lower acidity of the formamidinium cation compared to methylammonium. The chemical processes responsible for its thermal degradation appear to be quite complex as highlighted by the composition of the gaseous phase evolved during the process. The apparent activation energy values of the decomposition obtained from X-ray diffraction (XRD) (112 ± 9 kJ/mol) and differential scanning calorimetry (DSC) measurements (205 ± 20 and 410 ± 20 kJ/mol, respectively, for the first and second decomposition steps identified by the deconvolution procedure) reflect the different steps of the process observed by the two techniques. The thermodynamic properties of the more important decomposition channels and the enthalpy of formation of FAPI were estimated by combining the results of Knudsen effusion measurements.

Stabilizing lead halide perovskites with quaternary ammonium cations: the case of tetramethylammonium lead iodide.

Organoammonium lead halide perovskites, especially methylammonium lead iodide CH3NH3PbI3, are promising photovoltaic materials, but they are far from commercial applications due in particular to their thermal instability and moisture sensitivity. Here, we present a multitechnique study aimed at investigating the kinetic and thermodynamic stability of the simplest quaternary ammonium lead iodide, tetramethylammonium lead iodide N(CH3)4PbI3. The kinetics of thermal decomposition was studied by X-ray powder diffraction of samples treated in air at different temperatures combined with Rietveld quantitative phase analysis, and by the isoconversional analysis of differential thermal analysis measurements. Evidence for first order kinetics was obtained, with an activation energy of 280-290 kJ mol-1, suggesting that the breaking of the C-N bond is the rate determining step. The composition of the gas phase released under heating was investigated by Knudsen Effusion Mass Spectrometry, giving evidence for the occurrence of the process N(CH3)4PbI3(s) = PbI2(s) + N(CH3)3(g) + CH3I(g), consistent with the kinetic results. Decomposition pressures and thermodynamic properties were derived by Knudsen effusion mass loss experiments, obtaining values of 391.5 ± 2.0 kJ mol-1 and -577.4 ± 4.0 kJ mol-1 for the decomposition and formation enthalpies at 298 K, respectively. The reactivity towards water of N(CH3)4PbI3 was checked by XRD after total and prolonged immersion in water at room temperature. Overall, N(CH3)4PbI3 was found to be thermally much more stable than CH3NH3PbI3, both kinetically and thermodynamically, and much less prone to water-induced degradation, suggesting that the use of a quaternary ammonium cation may be an effective strategy in order to produce more stable materials.

Corrigendum: On the Thermal and Thermodynamic (In)Stability of Methylammonium Lead Halide Perovskites.

This corrects the article DOI: 10.1038/srep31896.

On the Thermal and Thermodynamic (In)Stability of Methylammonium Lead Halide Perovskites.

The interest of the scientific community on methylammonium lead halide perovskites (MAPbX3, X = Cl, Br, I) for hybrid organic-inorganic solar cells has grown exponentially since the first report in 2009. This fact is clearly justified by the very high efficiencies attainable (reaching 20% in lab scale devices) at a fraction of the cost of conventional photovoltaics. However, many problems must be solved before a market introduction of these devices can be envisaged. Perhaps the most important to be addressed is the lack of information regarding the thermal and thermodynamic stability of the materials towards decomposition, which are intrinsic properties of them and which can seriously limit or even exclude their use in real devices. In this work we present and discuss the results we obtained using non-ambient X-ray diffraction, Knudsen effusion-mass spectrometry (KEMS) and Knudsen effusion mass loss (KEML) techniques on MAPbCl3, MAPbBr3 and MAPbI3. The measurements demonstrate that all the materials decompose to the corresponding solid lead (II) halide and gaseous methylamine and hydrogen halide, and the decomposition is well detectable even at moderate temperatures (~60 °C). Our results suggest that these materials may be problematic for long term operation of solar devices.

Vaporization of the prototypical ionic liquid BMImNTf2 under equilibrium conditions: a multitechnique study.

The vaporization behaviour and thermodynamics of the ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide (BMImNTf2) were studied by combining the Knudsen Effusion Mass Loss (KEML) and Knudsen Effusion Mass Spectrometry (KEMS) techniques. KEML studies were carried out in a large temperature range (398-567) K by using effusion orifices with 0.3, 1, and 3 mm diameters. The vapor pressures so measured revealed no kinetically hindered vaporization effects and provided second-law vaporization enthalpies at the mean experimental temperatures in close agreement with literature. By exploiting the large temperature range covered, the heat capacity change associated with vaporization was estimated, resulting in a value of -66.8 J K(-1) mol(-1), much lower than that predicted from calorimetric measurements on the liquid phase and theoretical calculations on the gas phase. The conversion of the high temperature vaporization enthalpy to 298 K was discussed and the value Δ(l)(g)H(m)(298 K) = (128.6 ± 1.3) kJ mol(-1) assessed on the basis of data from literature and present work. Vapor pressure data were also processed by the third-law procedure using different estimations for the auxiliary thermal functions, and a Δ(l)(g)H(m)(298 K) consistent with the assessed value was obtained, although the overall agreement is sensitive to the accuracy of heat capacity data. KEMS measurements were carried out in the lower temperature range (393-467) K and showed that the largely prevailing ion species is BMIm(+), supporting the common view of BMImNTf2 vaporizing as individual, neutral ion pairs also under equilibrium conditions. By monitoring the mass spectrometric signal of this ion as a function of temperature, a second-law Δ(l)(g)H(m)(298 K) of 129.4 ± 7.3 kJ mol(-1) was obtained, well consistent with KEML and literature results. Finally, by combining KEML and KEMS measurements, the electron impact ionization cross section of BMIm(+) was estimated.

Natural evolution of Spitz nevi.

BACKGROUND: The natural evolution of melanocytic nevi is a complex, multifactorial process that can be studied by monitoring nevi on a long-term basis. METHODS: To assess the evolution pathway of Spitz nevi, lesions with clinical and dermoscopic features suggestive of Spitz nevi were monitored and baseline and follow-up images compared. RESULTS: Sixty-four patients (mean age 10.4 years) with lesions suggestive of Spitz nevi were included. Lesions were monitored for a mean follow-up period of 25 months. Upon side-by-side evaluation of baseline and follow-up images, 51 (79.7%) lesions showed an involution pattern and 13 (20.3%) lesions showed a growing or stable pattern. No significant differences were found between growing and involving lesions in terms of patient age and sex and the location and palpability of lesions. The great majority of growing lesions were pigmented or partially pigmented (92.3%), whereas 47.1% of lesions in involution were amelanotic (p = 0.005). CONCLUSION: In this series of lesions clinically and dermoscopically diagnosed as Spitz nevi, spontaneous involution seems to be the most common biologic behavior.

Spitz nevus: follow-up study of 8 cases of childhood starburst type and proposal for management.

Spitz nevus is an uncommon, benign melanocytic neoplasm that shares many clinical and histological features with melanoma. It presents clinical ambiguity that makes the diagnosis and management of the patient difficult. We present our experience in the management of Spitz nevus by rigorous dermoscopic long-term follow-up of 8 Spitz nevi in patients younger than 12 years. Dermoscopic images, acquired every 6 months, show evolution and modifications of these lesions. The aim of this paper is to better understand the long-term modifications of nevi with starburst pattern to avoid surgical excision of these lesions in the pediatric age group.

Dermoscopic and histopathologic diagnosis of equivocal melanocytic skin lesions: an interdisciplinary study on 107 cases.

BACKGROUND: Dermoscopy (dermatoscopy, epiluminescence microscopy) is increasingly employed for the preoperative detection of cutaneous melanoma; dermoscopic features of pigmented skin lesions have been previously defined using histopathology as the key to the code. In a preliminary study on 10 cases evaluated by nine dermoscopists and nine histopathologists, the authors experienced that when at least two dermoscopists disagree in evaluating a melanocytic lesion, even histopathologic consultations may give equivocal results. METHODS: One hundred seven melanocytic skin lesions, consecutively excised because of equivocal clinical and/or dermoscopic features, were retrospectively examined by eight dermoscopists and eight histopathologists; the diagnostic interobserver agreement was calculated by means of the Schouten k statistics. After histopathologic consultations, all 107 lesions underwent unblinded dermoscopic re-evaluation in order to find which dermoscopic features had given rise to histopathologic diagnostic difficulties. RESULTS: The interobserver ageement was good for both dermoscopy (k = 0.53) and histopathology (k = 0.74). Out of 48 cases evaluated by the dermoscopists in complete accordance, only 8 (16.7%) received at least one conflicting histopathologic diagnosis. Instead, among the remaining 59 cases with at least one disagreeing dermoscopic diagnosis, 21 (35.6%) received at least one disagreeing histopathologic diagnosis. The unblinded dermoscopic re-evaluation showed that five out of seven lesions with clear-cut regression structures were histopathologically controversial. CONCLUSIONS: At least for selected and reasonably difficult lesions, a diagnostic discrepancy among formally trained dermoscopists seems to be predictive for a diagnostic disagreement among histopathologists. Lesions showing clear-cut regression structures are prone to give some histopathologic disagreement.