Comparison of efficacy and safety of tretinoin 0.05% and glycolic acid peeling 70% in axillary and neck lesions of acanthosis nigricans: A single-blinded, randomized trial

BACKGROUND

Acanthosis nigricans is a non-inflammatory skin pigmentary disorder characterized by a dark, velvety appearance, primarily observed in the neck and axillary areas. It is commonly associated with obesity, diabetes, and insulin resistance. Although the primary treatment is correcting the underlying disorders, many aesthetic modalities have been established to improve appearance owing to cosmetic concerns.

AIMS

We aimed to compare and investigate the effectiveness and side effects of tretinoin 0.05% and glycolic acid 70% in treating acanthosis nigricans lesions of the axillary and neck area.

METHODS

This single-blinded, randomized trial recruited patients with neck or axillary involvement. Each patient was randomized to use cream tretinoin 0.05% every other night on one side, while the other side was treated with glycolic acid 70%, which was applied every 2 weeks at the clinic for four consecutive sessions. The study duration was 8 weeks, and patients were evaluated every 2 weeks based on their response to treatment, satisfaction, and side effects.

RESULTS

Thirty patients, including 14 with neck lesions and 16 with axillary lesions, were included. Tretinoin was significantly more effective for axillary lesions in terms of treatment response and patient satisfaction (p = 0.02 and p = 0.008, respectively). It was also shown that as the severity of the lesions increased, the response to treatment and patient satisfaction decreased, specifically when treating axillary lesions with glycolic acid (p = 0.02 and p = 0.03, respectively).

CONCLUSION

Neither method was significantly effective for neck lesions. However, tretinoin 0.05% was shown to be more efficacious in treating axillary lesions of acanthosis nigricans, despite causing minimal side effects.

Quality Evaluation of New Types of Layered Composites for Flooring Materials

The need, or even the obligation, to take care of the natural environment compels a search for new technological solutions, or for known solutions to be adapted to new applications. The maxim is 'don't harm, but improve the world for future generations'. In the wood industry in particular, given that it is based on a natural raw material, we must look for ecological solutions. Trees grow, but the demand for wood exceeds the volume of tree growth. In industrial manufacturing, one of the ways to make full use of wood is through chipless processing, which occurs during rotary cutting (peeling). In addition, wood is a natural material, each fragment of which has a range of properties. In addition, wood defects in quality manipulation generate a lot of waste. The aim of this study was to analyse the quality effect of the tested layered composites for flooring materials on production application. The practical purpose was to exchange actual sawing-based production for chipless production. The composite base layers were made of pine wood (Pinus L.) veneers with differing quality classes. The samples were subjected to three-point bending tests to calculate the moduli of elasticity and stiffness, which are the most important parameters. Because both analysed parameters describe product quality, the analyses were based on the creation of Shewhart control charts for each parameter. In theory, these control charts are tools for analysing whether the production process is stable and yields predictable results. To have full control over the process, five elements have to be applied: central line (target), two types of control lines (upper and lower) and two types of specification lines (upper and lower). New types of layered composites for flooring may be applied to production once verified using Shewhart control charts. It turns out that it is possible to produce the base layer of the flooring materials using the rotary cutting (peeling) method without having to analyse the quality of the raw material. This is a way to significantly increase the efficiency of production in every element of manufacturing.

Polyhomogeneous spin-0 fields in Minkowski space-time

The asymptotic behaviour of massless spin-0 fields close to spatial and null infinity in Minkowski space-time is studied by means of Friedrich's cylinder at spatial infinity. The results are applied to a system of equations called the good-bad-ugly which serves as a model for the Einstein field equations in generalized harmonic gauge. The relation between the logarithmic terms (polyhomogeneity) appearing in the solution obtained using conformal methods and those obtained by means of a heuristic method based on Hörmander's asymptotic system is discussed. This review article is based on Duarte et al. (Duarte et al. 2023 Class. Quantum Gravity 40, 055002. (doi:10.1088/1361-6382/acb47e)); Gasperín & Pinto (Gasperín & Pinto 2023 Spin-0 fields and the NP-constants close to spatial infinity in Minkowski spacetime. J. Math. Phys. 64, 082502. (doi:10.1063/5.0158746)). This article is part of a discussion meeting issue 'At the interface of asymptotics, conformal methods and analysis in general relativity'.

The case against smooth null infinity IV: Linearized gravity around Schwarzschild-an overview

This paper is the fourth in a series dedicated to the mathematically rigorous asymptotic analysis of gravitational radiation under astrophysically realistic set-ups. It provides an overview of the physical ideas involved in setting up the mathematical problem, the mathematical challenges that need to be overcome once the problem is posed, as well as the main new results we will obtain in upcoming work. From the physical perspective, this includes a discussion of how post-Newtonian theory provides a prediction on the gravitational radiation emitted by [Formula: see text] infalling masses from the infinite past in the intermediate zone, i.e. up to some finite advanced time. From the mathematical perspective, we then take this prediction, together with the condition that there be no incoming radiation from [Formula: see text], as a starting point to set up a scattering problem for the linearized Einstein vacuum equations around Schwarzschild and near spacelike infinity, and we outline how to solve this scattering problem and obtain the asymptotic properties of the scattering solution near [Formula: see text] and [Formula: see text]. The full mathematical details will be presented in the sequel to this paper. This article is part of a discussion meeting issue 'At the interface of asymptotics, conformal methods and analysis in general relativity'.

Peeling with retinoic acid in microemulsion for treatment of melasma: A double-blind randomized controlled clinical study

OBJECTIVE

To evaluate the clinical efficacy of peeling with a microemulsion formulation containing 1% retinoic acid.

MATERIALS AND METHODS

After development of the product, 60 patients with melasma were randomly divided into three groups (n = 20): Group 1-application of conventional 1% retinoic acid peeling (RA 1%). Group 2-application of 1% retinoic acid peeling in microemulsion (RA 1%M). Group 3-Application of placebo. The groups were submitted to four peeling sessions, fortnightly on Days 0, 15, 30, and 45, and analyzed at the time intervals of 0, 15, 30, 45, and 60 days. Evaluation was made by using the Melasma Area and Severity Index (MASI) and Melasma Quality of Life (MelasquoL) instrument. Hemato-biochemical parameters were also evaluated at Days 0 and 60. After obtaining the results, normality was evaluated by means of the Kolmogorov-Smirnov test and afterwards, the following tests were applied: Friedman statistical (to test the effect of the treatments on the MASI index); Wilcoxon, (for comparison between pairs to test the effect of treatments on the MelasQoL index); Kruskal-Wallis, (to test the differences between the groups); and Mann-Whitney, (comparisons between treatments). The level of significance adopted was 5% (α = 0.05).

RESULTS

The three groups presented a significant reduction in the MASI index, indicating the effect of all the treatments on reducing the melasma (p < 0.001). A significant reduction in the stains was observed with the use of retinoic acid peeling delivered in microemulsion (62%) when compared with the conventional peeling with 1% retinoic acid in a conventional vehicle (26%) and the placebo (12%). There was also a significant reduction in the MelasQoL index (sum of all the aspects) in the three groups, indicating the effect of all the treatments, including the placebo, on the overall quality of life of those with melasma. However, RA 1%M the treatment that promoted the greatest effect on the quality of life of individuals. In percentage terms, the RA 1%M provided a mean reduction of 30% in the MelasQoL index, against 13% of the conventional treatment and only 4% of the placebo. When the hemato-biochemical parameters were compared on Days 0 and 60, there were no significant changes in the results.

CONCLUSION

The chemical peeling performed with RA 1%M was effective for the treatment of melasma, and was shown to be superior to the peeling performed with retinoic acid in a conventional vehicle, in reducing the stains and improving the quality of life of patients.

Effects of high hydrostatic pressure on peelability and quality of crayfish(Procambarus clarkii)

BACKGROUND

Peeling of crayfish is a very important process in production. Crayfish peeling by machine can increase production efficiency and enhance safety in the production process. The tight muscle-shell attachment causes difficulty in peeling freshly caught crayfish. However, few studies have explored the changes in crayfish quality under favorable shell-loosening treatments.

RESULTS

In this study, the shell-loosening properties of crayfish and changes in crayfish quality, microstructure and protein fluorescent features were investigated after high hydrostatic pressure (HHP) treatment. New methods were established to measure the peeling performance of crayfish, which are peelability and meat yield rate (MYR). The normalization of peelability and MYR were verified by different weights of crayfish tails and different treatments. The peeling effect of HHP-treated crayfish was evaluated by a new quantitative measurement method, and MYR was calculated. The results showed that all the HHP treatments reduced crayfish peeling work and increased MYR. The HHP treatment provided better crayfish quality in terms of texture and color and enlarged the shell-loosening gap. Among all HHP treatments, 200 MPa treatment exhibited lower peeling work, higher MYR and an expansion of the shell-loosening gap, reaching up to 573.8 μm. At the same time, 200 MPa treatment could maintain crayfish quality.

CONCLUSION

The findings outlined above suggest that high pressure is a promising method for loosening crayfish shells. 200 MPa is an optimal HHP treatment condition for crayfish peeling, exhibiting a promising application in industrial processing. © 2023 Society of Chemical Industry.

Fabrication, Characterization, and Microbial Biodegradation of Transparent Nanodehydrated Bioplastic (NDB) Membranes Using Novel Casting, Dehydration, and Peeling Techniques

NDBs were fabricated from gum Arabic (GA) and polyvinyl alcohol (PVA) in different ratios using novel techniques (casting, dehydration, and peeling). The GA/PVA blends were cast with a novel vibration-free horizontal flow (VFHF) technique, producing membranes free of air bubble defects with a homogenous texture, smooth surface, and constant thickness. The casting process was achieved on a self-electrostatic template (SET) made of poly-(methyl methacrylate), which made peeling the final product membranes easy due to its non-stick behavior. After settling the casting of the membranous, while blind, the sheets were dried using nanometric dehydration under a mild vacuum stream using a novel stratified nano-dehydrator (SND) loaded with P2O5. After drying the NDB, the dry, smooth membranes were peeled easily without scratching defects. The physicochemical properties of the NDBs were investigated using FTIR, XRD, TGA, DTA, and AFM to ensure that the novel techniques did not distort the product quality. The NDBs retained their virgin characteristics, namely, their chemical functional groups (FTIR results), crystallinity index (XRD data), thermal stability (TGA and DTA), and ultrastructural features (surface roughness and permeability), as well as their microbial biodegradation ability. Adding PVA enhanced the membrane's properties except for mass loss, whereby increasing the GA allocation in the NDB blend reduces its mass loss at elevated temperatures. The produced bioplastic membranes showed suitable mechanical properties for food packaging applications and in the pharmaceutical industry for the controlled release of drugs. In comparison to control samples, the separated bacteria and fungi destroyed the bioplastic membranes. Pseudomonas spp. and Bacillus spp. were the two main strains of isolated bacteria, and Rhizobus spp. was the main fungus. The nano-dehydration method gave the best solution for the prompt drying of water-based biopolymers free of manufacturing defects, with simple and easily acquired machinery required for the casting and peeling tasks, in addition to its wonderful biodegradation behavior when buried in wet soil.

Cooperative Tridentate Hydrogen-Bonding Interactions Enable Strong Underwater Adhesion

Multidentate hydrogen-bonding interactions are a promising strategy to improve underwater adhesion. Molecular and macroscale experiments have revealed an increase in underwater adhesion by incorporating multidentate H-bonding groups, but quantitatively relating the macroscale adhesive strength to cooperative hydrogen-bonding interactions remains challenging. Here, we investigate whether tridentate alcohol moieties incorporated in a model epoxy act cooperatively to enhance adhesion. We first demonstrate that incorporation of tridentate alcohol moieties leads to comparable adhesive strength with mica and aluminum in air and in water. We then show that the presence of tridentate groups leads to energy release rates that increase with an increase in crack velocity in air and in water, while materials lacking these groups do not display rate-dependent adhesion. We model the rate-dependent adhesion to estimate the activation energy of the interfacial bonds. Based on our data, we estimate the lifetime of these bonds to be between 2 ms and 6 s, corresponding to an equilibrium activation energy between 23k_BT and 31k_BT. These values are consistent with tridentate hydrogen bonding, suggesting that the three alcohol groups in the Tris moiety bond cooperatively form a robust adhesive interaction underwater.

A useful technique of starting internal limiting membrane peeling from the edge of the internal limiting membrane defect in epiretinal membrane surgery

Clinicians should be aware that internal limiting membrane (ILM) defects may occur concurrently with epiretinal membrane, and starting ILM peeling at the ILM defect margin may be useful in such cases.

Abstract

We describe a useful surgical technique for the treatment of idiopathic epiretinal membrane with concurrent internal limiting membrane (ILM) defect, in which ILM peeling was started from the ILM defect margin. A dissociated optic nerve fiber layer-like appearance on fundus examination and optical coherence tomography may suggest an ILM defect.

Capillary Transfer of Self-Assembled Colloidal Crystals

Colloidal self-assembly has attracted significant interest in numerous applications including optics, electrochemistry, thermofluidics, and biomolecule templating. To meet the requirements of these applications, numerous fabrication methods have been developed. However, these are limited to narrow ranges of feature sizes, are incompatible with many substrates, and/or have low scalability, significantly limiting the use of colloidal self-assembly. In this work, we study the capillary transfer of colloidal crystals and demonstrate that this approach overcomes these limitations. Enabled by capillary transfer, we fabricate 2D colloidal crystals with nano-to-micro feature sizes spanning 2 orders of magnitude and on typically challenging substrates including those that are hydrophobic, rough, curved, or structured with microchannels. We developed and systemically validated a capillary peeling model, elucidating the underlying transfer physics. Due to its high versatility, good quality, and simplicity, this approach can expand the possibilities of colloidal self-assembly and enhance the performance of applications using colloidal crystals.

Long-Term Results of Adjunct Autologous Platelet-Rich Plasma in Lamellar Macular Hole Surgery Showing Lasting Restoration of Foveal Anatomy

The aim of this study was to evaluate the long-time results of highly concentrated autologous platelet-rich plasma (PRP) used as an adjunct in lamellar macular hole (LMH) surgery. Nineteen eyes of nineteen patients with progressive LMH were enrolled in this interventional case series, on which 23/25-gauge pars plana vitrectomy was performed and 0.1 mL of highly concentrated autologous platelet-rich plasma was applied under air tamponade. Posterior vitreous detachment was induced, and the peeling of tractive epiretinal membranes, whenever present, was performed. In cases of phakic lens status, combined surgery was carried out. Postoperatively, all patients were instructed to remain in a supine position for the first two postoperative hours. Best-corrected visual acuity (BCVA) testing, microperimetry, and spectral domain optical coherence tomography (SD-OCT) were carried out preoperatively and at minimum 6 months (in median 12 months) postoperatively. Foveal configuration was postoperatively restored in 19 of 19 patients. Two patients who had not undergone ILM peeling showed a recurring defect at 6-month follow-up. Best-corrected visual acuity improved significantly from 0.29 ± 0.08 to 0.14 ± 0.13 logMAR (p = 0.028, Wilcoxon signed-rank test). Microperimetry remained unchanged (23.38 ± 2.53 preoperatively; 23.0 ± 2.49 dB postoperatively; p = 0.67). No patients experienced vision loss after surgery, and no significant intra- or postoperative complications were observed. Using PRP as an adjunct in macular hole surgery significantly improves morphological and functional outcomes. Additionally, it might be an effective prophylaxis to further progression and also the formation of a secondary full-thickness macular hole. The results of this study might contribute to a paradigm shift in macular hole surgery towards early intervention.

Efficacy of Jessener solution versus intralesional steroid in treatment of alopecia areata

BACKGROUND

Alopecia areata is an autoimmune condition that causes non-scarring hair loss. To date, there is no single cure and treatment remains challenging.

OBJECTIVES

To evaluate the efficacy of Jessener solution versus intralesional steroid in treatment of Alopecia Areata.

METHODS

This study included 40 patients who presented with multifocal patchy alopecia areata (AA). For each patient, three patches were randomly selected to be treated one with intralesional steroid, another with topical Jessner solution and the third with normal saline. Three sessions were done 3 weeks apart and were followed up for 3 months. Response was assessed clinically and by trichoscope.

RESULTS

Fifteen percent of patches coated with Jessner or injected with steroids showed an excellent response while 20% of patches coated with Jessner and 32.5% patches injected with steroids showed a good response. A significant difference was observed between the three modalities of treatment regarding the prognostic score for response (p < 0.001) as patches coated with Jessner and those steroid injected showed a significant higher response rate than patches injected with saline (p < 0.001) while no significant difference was reported between patches either treated with Jessner or steroids (p > 0.05).

CONCLUSION

Jessners solution can be a novel and feasible and well tolerated modality of treatment for patients suffering from alopecia areata.

Demystifying the mechanism of action of professional facial peeling: In-vivo visualization and quantification of changes in inflammation, melanin and collagen using Vivascope® and ConfoScan®

Professional peeling using chemicals (chemical peeling) is a popular non-surgical procedure commonly used for the treatment for photoaging, pigmentary disorders, scarring, fine lines, and wrinkles. The objective of our case study was to elucidate the mechanism of action of professional peels/peeling. For proof-of-concept, we used a commercial blended peel containing trichloroacetic acid and lactic acid. The facial peeling was performed by a physician on four subjects. These subjects were followed over time in the clinic to take clinical pictures and monitor surface and anatomical changes in inflammation, melanin, and collagen at regular intervals post-peel (5 min, 48 h, and day 9). Dermoscope and Vivascope® were used to image surface and subsurface anatomical changes, respectively, and ConfoScan® was used to quantify aforementioned anatomical changes. Based on Vivascope and ConfoScan analysis, we could see clear visual clinical evidence of controlled injury-healing mechanism of peel's action: immediate but transient onset of inflammation within 5 min (indicate injury response by skin), followed by melanin redistribution evident at 48 h (indicate activation of skin's defense system), and remodeled fibrous collagen network without any inflammatory cells on day 9 (healing response). To our knowledge, this is the first ever clinical study to deconvolute the mysterious mechanism of action of peels, in-vivo.

Application of high-pressure assisted thermal processing (PATP) at pilot scale for replacing conventional maturation and thermal cooking in whiteleg shrimp (Litopenaeus vannamei)

BACKGROUND

The aim of this work was to examine for the first time the use of high-pressure assisted thermal processing (PATP) (100, 350, 600 MPa; 100 °C; 3 min) at pilot scale for replacing shrimp (Litopenaeus vannamei) maturation and cooking, analyzing its impact on peeling yield, color, texture and sensory properties. Shrimps subjected to conventional maturation (ice; 2 days) and thermal cooking (100 °C; boiling water, 3 min) were used as controls.

RESULTS

PATP treatments at 100-350 MPa improved manual peelability over the control (P ≤ 0.05), maintaining similar peeling yield, color (L*, a*, b*), texture (shear force, shear work) and sensory properties (appearance before and after peeling, flavor, firmness; P < 0.05). However, increasing pressure to 600 MPa clearly overprocessed the samples, making it impossible to remove all the meat from the shell and resulting in a softer texture, 4.1% lower peeling yield and worse sensory quality (P ≤ 0.05).

CONCLUSION

PATP (< 350 MPa; 100 °C) could be an alternative to replace conventional maturation and thermal cooking in the production of cooked shrimps, reducing processing time from days to minutes by performing both processes in a single step. © 2022 Society of Chemical Industry.

Peeling dynamics of fluid membranes bridged by molecular bonds: moving or breaking

Biological adhesion is a critical mechanical function of complex organisms. At the scale of cell–cell contacts, adhesion is remarkably tunable to enable both cohesion and malleability during development, homeostasis and disease. It is physically supported by transient and laterally mobile molecular bonds embedded in fluid membranes. Thus, unlike specific adhesion at solid–solid or solid–fluid interfaces, peeling at fluid–fluid interfaces can proceed by breaking bonds, by moving bonds or by a combination of both. How the additional degree of freedom provided by bond mobility changes the mechanics of peeling is not understood. To address this, we develop a theoretical model coupling diffusion, reactions and mechanics. Mobility and reaction rates determine distinct peeling regimes. In a diffusion-dominated Stefan-like regime, bond motion establishes self-stabilizing dynamics that increase the effective fracture energy. In a reaction-dominated regime, peeling proceeds by travelling fronts where marginal diffusion and unbinding control peeling speed. In a mixed reaction–diffusion regime, strengthening by bond motion competes with weakening by bond breaking in a force-dependent manner, defining the strength of the adhesion patch. In turn, patch strength depends on molecular properties such as bond stiffness, force sensitivity or crowding. We thus establish the physical rules enabling tunable cohesion in cellular tissues and in engineered biomimetic systems.

Competition between Sliding and Peeling of Graphene Nanoribbons under Horizontal Drag

In the process of graphene nanoribbons’ (GNRs) preparation and measurement, mechanical methods such as lifting and dragging are inevitably used to move GNRs, and manipulation of GNRs using these approaches results in intriguing responses such as peeling and sliding. Understanding the mechanical behaviors of GNRs is crucial for the effective use of mechanical deformation as a tool for the measurement and characteristics of low-dimensional material properties. Here, we explore intricate coupling behaviors of peeling and sliding of GNRs under horizontal drag. Using molecular dynamics simulation, we explore effects of lifting height, dragging velocity, length, and orientation of GNRs on mechanical behaviors. We reveal a competition between sliding and peeling of GNRs under horizontal drag and provide a phase diagram. The peeling behavior is found to be originated from the decrease of sliding velocity caused by the sinking of tail atoms. The results not only advance our insightful understanding of the underlying mechanism of different mechanical responses of GNRs but may also guide the precise manipulations of nano surfaces and interfaces.

Spotlight on the Internal Limiting Membrane Technique for Macular Holes: Current Perspectives

Pars plana vitrectomy has become the standard procedure for primary macular holes (MHs) repair, including the removal of the posterior cortical vitreous, the stripping of eventual epiretinal membranes, and finally an intraocular gas tamponade. During this procedure, peeling the internal limiting membrane (ILM) has been proven to increase closure rates and avoid postoperative reopening in several researches. In fact, even in large MHs more than 400 µm, the advantage of peeling off the ILM was highlighted by better anatomical closure rates. Nevertheless, some authors suggested that ILM peeling is not always essential, because it generates various side effects in retinal structure and function. Furthermore, the ideal amount of ILM peeling and the most effective strategies for removing the ILM are still subject of research. Different surgical modifications have been reported as alternatives to traditional peeling in certain clinical settings, including ILM flaps, ILM scraping, and foveal sparing ILM peeling. As regards large MHs, the introduction of ILM inverted flap appeared as a game changer, offering a significantly higher >90% closure rate when compared to traditional ILM peeling. Modifications to inverted ILM flap procedures have been claimed in recent years, in order to define the best area and direction of ILM peeling and its correlation with functional outcomes. Moreover, several innovations saw the light in the setting of recurrent MHs, such as ILM free flap transposition, inverted ILM flap combined autologous blood clot technique, neurosensory retinal flap, and human amniotic membrane (HAM) plug, claiming higher anatomical success rate also in those complex settings. In conclusion, the aim of this review is to report how the success rate of contemporary macular surgery has grown since the turn of the century, especially for big and chronic MHs, analyzing in which way ILM management became a crucial point of this kind of surgery.

Role of Thin Film Adhesion on Capillary Peeling

The capillary force can peel off a substrate-attached film if the adhesion energy (G_w) is low. Capillary peeling has been used as a convenient, rapid, and nondestructive method for fabricating free-standing thin films. However, the critical value of G_w, which leads to the transition between peeling and sticking, remains largely unknown. As a result, capillary peeling remains empirical and applicable to a limited set of materials. Here, we investigate the critical value of G_w and experimentally show the critical adhesion (G_w,c) to scale with the water-film interfacial energy (≈0.7γ_fw), which corresponds well with our theoretical prediction of G_w,c = γ_fw. Based on the critical adhesion, we propose quantitative thermodynamic guidelines for designing thin film interfaces that enable successful capillary peeling. The outcomes of this work present a powerful technique for thin film transfer and advanced nanofabrication in flexible photovoltaics, battery materials, biosensing, translational medicine, and stretchable bioelectronics.

Eco-Friendly Peelable Active Nanocomposite Films Designed for Biological and Chemical Warfare Agents Decontamination

In the context of imminent threats concerning biological and chemical warfare agents, the aim of this study was the development of a new method for biological and chemical decontamination, employing non-toxic, film-forming, water-based biodegradable solutions, using a nano sized reagent together with bentonite as trapping agents for the biological and chemical contaminants. Bentonite-supported nanoparticles of Cu, TiO₂, and Ag were successfully synthesized and dispersed in a polyvinyl alcohol (PVA)/glycerol (GLY) aqueous solution. The decontamination effectiveness of the proposed solutions was evaluated by qualitative and quantitative analytical techniques on various micro-organisms, with sulfur mustard (HD) and dimethyl methylphosphonate (DMMP) as contaminants. The results indicate that the peelable active nanocomposite films can be successfully used on contaminated surfaces to neutralize and entrap the hazardous materials and their degradation products. Mechanical and thermal characterization of the polymeric films was also performed to validate the decontamination solution's potential as peelable-film generating materials. The removal efficacy from the contaminated surfaces for the tested micro-organisms varied between 93% and 97%, while for the chemical agent HD, the highest decontamination factor obtained was 90.89%. DMMP was almost completely removed from the contaminated surfaces, and a decontamination factor of 99.97% was obtained.

Registry-Dependent Peeling of Layered Material Interfaces: The Case of Graphene Nanoribbons on Hexagonal Boron Nitride

Peeling of layered materials from supporting substrates, which is central for exfoliation and transfer processes, is found to be dominated by lattice commensurability effects in both low and high velocity limits. For a graphene nanoribbon atop a hexagonal boron nitride surface, the microscopic peeling behavior ranges from stick-slip, through smooth-sliding, to pure peeling regimes, depending on the relative orientation of the contacting surfaces and the peeling angle. The underlying mechanisms stem from the intimate relation between interfacial registry, interlayer interactions, and friction. This, in turn, allows for devising simple models for extracting the interfacial adhesion energy from the peeling force traces.

Ultrasound, infrared and its assisted technology, a promising tool in physical food processing: A review of recent developments

Traditional food processing techniques can no longer meet the ever increasing demand for high quality food across the globe due to its low process efficiency, high energy consumption and low product yield. This review article is focused on the mechanism and application of Infrared (IR) and ultrasound (US) technologies in physical processing of food. We herein present the individual use of IR and US (both mono-frequency and multi-frequency levels) as well as IR and US supported with other thermal and non-thermal technologies to improve their food processing performance. IR and US are recent thermal and non-thermal technologies which have now been successfully used in food industries to solve the demerits of conventional processing technologies. These environmentally-friendly technologies are characterized by low energy consumption, reduced processing time, high mass-transfer rates, better nutrient retention, better product quality, less mechanical damage and improved shelf life. This work could be, with no doubt, useful to the scientific world and food industries by providing insights on recent advances in the use of US and IR technology, which can be applied to improve food processing technologies for better quality and safer products.

Energizing ASTM lap joint fracture standards

Several ASTM standards on the fracture of glued and welded joints need attention because they do not consider the Griffith energy criterion of cracking which was proposed a century ago. It is almost as if Griffith never existed because the ASTM definition of failure is the stress criterion postulated by Galileo in 1638 in which stress at failure (i.e. strength = force/area) is defined as the determinant of fracture. Irene Martinez Villegas (Villegas, Rans 2021 Phil. Trans. R. Soc. A 376, 20200296. (doi:10.1098/rsta.2020.0296)) shows in this volume that attempts to use ASTM D5868 to standardize welded composite (carbon fibre reinforced polymer, CFRP) lap joints reveal major problems. First, the test is a low angle bend-peel test; not shear. Second, the energy required to break the joint is not emphasized so that joints may have high strength properties but also low toughness; third, the fracture force is not proportional to the lap joint area so the concept of strength independent of sample size is false; fourth, as the CFRP panels are made thicker, the strength rises at constant overlap area so the strength can be any value you want; fifth, the strength of larger joints goes down; this is the size effect noted in many bend-cracking tests, much as Galileo suggested for bent beam fracture in his famous book 'the larger the machine, the greater its weakness'. The purpose of this paper is to demonstrate that poor ASTM 'shear strength' standards should be replaced by a definition of welded lap joint performance based on Griffith's energy conservation argument in which fracture surface energy is the main parameter resisting failure. The foundation of this Griffith-style lap joint analysis for long cracks goes back to 1975 but has been largely ignored until now because it does not fit the Griffith equation for cracked sheets, has no 'stress intensity factor', and travels at constant speed, not accelerating like the standard Griffith tension crack. This study of tensile delamination shows that a long lap crack is not driven by stress near the crack but by changes in stored elastic energy in the stretched strips remote from the crack tip, while strain energy release rate is negative. It would be more appropriate to call this lap failure a tensile delamination crack. This article is part of a discussion meeting issue 'A cracking approach to inventing new tough materials: fracture stranger than friction'.

Ethylene treatment of "Maekawa-Jiro" persimmon affects peel characteristics and consequently, enables boil-peeling

In a previous study, we reported that ethylene treatment facilitated boil-peeling in persimmons and in several other fruits; however, the mechanism underlying the facilitating effect of ethylene was not examined in detail. Thus, in this study, we investigated the effect of ethylene treatment on the peel characteristics of persimmons, that facilitated boil-peeling, using chemical, genomic, and histochemistry analyses. The results of the study showed that the ethylene-related genes, DK-ACS1 and DK-ACO2, and the pectinase-active gene DKPG were not expressed, even though a minor increase in ethylene generation was observed after ethylene treatment. Conversely, significant accumulation of toluidine blue O and ruthenium red dyes were observed in the sarcocarp and exocarp of the fruits, indicating an increase in the quantity of polysaccharides, including pectic substances, at the site. The results also indicate that the increased cellulase activity observed in the pericarp of the fruits may be due to the aging of the fruits, and not necessarily as a result of ethylene treatment. Furthermore, ethylene treatment increased the quantity of polysaccharides, including pectic substances, directly below the pericarp, which caused the dissolution of the site, resulting in peeling. This study provides new insights on the effect of ethylene on boil-peeling in persimmons and provides a foundation for future research studying the effect of heat treatment in the peeling of fruits or tomato.

Changes in the Ganglion Cell Complex after Inner Limiting Membrane Peeling for Epiretinal Membrane in Glaucoma Patients

BACKGROUND

Epiretinal membrane (ERM) is a disease that affects the vitreoretinal interface and causes metamorphopsia, anorthopia, and decreased visual acuity. In this study, ERM patients who underwent internal limiting membrane (ILM) peeling were classified as those with glaucoma (Group G) and a control group (Group C). Changes in ganglion cell complex (GCC) thickness were compared between these groups to investigate whether such changes had an effect on progression of glaucoma from structural change.

METHODS

This was a retrospective, observational study that included 27 eyes of 27 patients. Group C included 22 eyes, and Group G included 5 eyes. Patients underwent ILM peeling, and cataract surgery was combined with vitrectomy for 16 phakic eyes; 2 phakic eyes and 9 aphakic eyes were treated only with vitrectomy. GCC thickness was measured preoperatively and at 2 weeks and 1, 3, and 6 months postoperatively, and these values and the rates of thinning were compared between the two groups.

RESULTS

The mean age of patients was 66.7±12.8 years (range 30-84 years). There was no significant difference between groups in the thickness of the GCC or its rate of thinning after ILM peeling.

CONCLUSIONS

The present results suggest that this procedure does not cause structural exacerbation of glaucoma in glaucoma patients. Although further studies of the functional effects of ILM peeling are required, the present results suggest that there is no significant difference between the two groups.

Melasma treatment: a systematic review

Melasma is a common chronic refractory disorder of pigmentation affecting people with darker skin types. Overall prevalence varies between 8.8% and 40%, depending on the ethnicity of the population and the geographical area. Therapeutic management of melasma is challenging, with high recurrence rates which significant impacts on the quality of life. No single treatment is universally efficacious. Systemic treatments with tranexamic acid and polypodium leucotmatous had promising results, although the former was related to systemic side effects. Microneedling and peeling were also efficacious, although their superiority to topical hydroquinone, the gold standard in melasma treatment, remains to be established. Similarly, laser and light devices have been beneficial. However, recurrence rates remain high in all treatment groups. Combination therapies, either in double or triple combinations yielded the best results when compared to single terapies. Treatment choice should be made after Wood's lamp examination, as well as dermatoscopic evaluation, in order to select the best treatment option, targeted at each melasma subtype.

Origin of High Friction at Graphene Step Edges on Graphite

On graphite, friction is known to be more than an order of magnitude larger at step edge defects as compared to on the basal plane, especially when the counter surface slides from the lower terrace of the step to the upper terrace. Very different mechanisms have been proposed to explain this phenomenon, including atomic interactions between the counter surface and step edge (without physical deformation) and buckling or peeling deformation of the upper graphene terrace. Here, we use atomic force microscopy (AFM) and reactive molecular dynamic (MD) simulations to capture and differentiate the mechanisms proposed to cause high friction at step edges. AFM experiments reveal the difference between cases of no deformation and buckling deformation, and the latter case is attributed to the physical stress exerted by the sliding tip. Reactive MD simulations explore the process of peeling deformation due to tribochemical bond formation between the tip and the step edge. Combining the results of AFM experiments and MD simulations, it is found that each mechanism has identifiable and characteristic features in the lateral force and vertical height profiles recorded during the step-up process. The results demonstrate that buckling and peeling deformation of the graphene edge rarely occur under typical AFM experimental conditions and thus are unlikely to be the origin of high friction at step edges in most measurements. Instead, the high step-up friction is due to stick-slip behavior facilitated by the topographical change and atomic interactions between the tip and step edge without deformation of the graphene itself.

Effect of Glycation on Interlamellar Bonding of Arterial Elastin

BACKGROUND

Interlamellar bonding in the arterial wall is often compromised by cardiovascular diseases. However, several recent nationwide and hospital-based studies have uniformly reported reduced risk of thoracic aortic dissection in patients with diabetes. As one of the primary structural constituents in the arterial wall, elastin plays an important role in providing its interlamellar structural integrity.

OBJECTIVE

The purpose of this study is to examine the effects of glycation on the interlamellar bonding properties of arterial elastin.

METHODS

Purified elastin network was isolated from porcine descending thoracic aorta and incubated in 2 M glucose solution for 7, 14 or 21 days at 37 °C. Peeling and direct tension tests were performed to provide complimentary information on understanding the interlamellar layer separation properties of elastin network with glycation effect. Peeling tests were simulated using a cohesive zone model (CZM). Multiphoton imaging was used to visualize the interlamellar elastin fibers in samples subjected to peeling and direct tension.

RESULTS

Peeling and direct tension tests show that interlamellar energy release rate and strength both increases with the duration of glucose treatment. The traction at damage initiation estimated for the CZM agrees well with the interlamellar strength measurements from direct tension tests. Glycation was also found to increase the interlamellar failure strain of arterial elastin. Multiphoton imaging confirmed the contribution of radially running elastin fibers to resisting dissection.

CONCLUSIONS

Nonenzymatic glycation reduces the propensity of arterial elastin to dissection. This study also suggests that the CZM effectively describes the interlamellar bonding properties of arterial elastin.

Vitrectomy for the removal of idiopathic epiretinal membrane with or without internal limiting membrane peeling: a meta-analysis

Purpose:

The aim of this study is to analyze the effect of internal limiting membrane peeling in removal of idiopathic epiretinal membranes through meta-analysis.

Methods:

We searched PubMed for studies published until 30 April 2018. Inclusion criteria included cases of idiopathic epiretinal membranes, treated with vitrectomy with or without internal limiting membrane peeling. Exclusion criteria consisted of coexisting retinal pathologies and use of indocyanine green to stain the internal limiting membrane. Sixteen studies were included in our meta-analysis. We compared the results of surgical removal of epiretinal membrane, with or without internal limiting membrane peeling, in terms of best-corrected visual acuity and anatomical restoration of the macula (central foveal thickness). Studies or subgroups of patients who had indocyanine green used as an internal limiting membrane stain were excluded from the study, due to evidence of its toxicity to the retina.

Results:

Regarding best-corrected visual acuity levels, the overall mean difference was –0.29 (95% confidence interval: –0.319 to –0.261), while for patients with internal limiting membrane peeling was –0.289 (95% confidence interval: –0.334 to –0.244) and for patients without internal limiting membrane peeling was –0.282 (95% confidence interval: –0.34 to –0.225). Regarding central foveal thickness levels, the overall mean difference was –117.22 (95% confidence interval: –136.70 to –97.74), while for patients with internal limiting membrane peeling was –121.08 (95% confidence interval: –151.12 to –91.03) and for patients without internal limiting membrane peeling was –105.34 (95% confidence interval: –119.47 to –96.21).

Conclusion:

Vitrectomy for the removal of epiretinal membrane combined with internal limiting membrane peeling is an effective method for the treatment of patients with idiopathic epiretinal membrane.

Condensation Induced Blistering as a Measurement Technique for the Adhesion Energy of Nanoscale Polymer Films

Polymeric coatings having micro-to-nanoscale thickness show immense promise for enhancing thermal transport, catalysis, energy conversion, and water collection. Characterizing the work of adhesion (G) between these coatings and their substrates is key to understanding transport physics as well as mechanical reliability. Here, we demonstrate that water vapor condensation blistering is capable of in situ measurement of work of adhesion at the interface of polymer thin films with micrometer spatial resolution. We use our method to characterize adhesion of interfaces with controlled chemistry such as fluorocarbon/fluorocarbon (CF_n/CF_m, n, m = 0-3), fluorocarbon/hydrocarbon (CF_n/CH_m), fluorocarbon/silica (CF_n/SiO₂), and hydrocarbon/silica (CH_n/SiO₂) interfaces showing excellent agreement with adhesion energy measured by the contact angle approach. We demonstrate the capability of our condensation blister test to achieve measurement spatial resolutions as low as 10 μm with uncertainties of ∼10%. The outcomes of this work establish a simple tool to study interfacial adhesion.

Effluent free infrared radiation assisted dry-peeling of ginger rhizome: A feasibility and quality attributes

Infrared radiation (IR)-assisted peeling is one of the effulent free, environtment friendly emerging technique for tender fruit and vegetables. In this study standerdization and optimization of the infrared assisted dry-peeling method was carried out for ginger rhizome. During the investigation, the effects of selected independent parameters like infrared temperature (300-400 °C), heater to product surface spacing (10-30 mm), and treatment time (120-300 s) were studied on the peeling feasibility and quality as dependent variables. The experimental conditions were designed through CCRD statistical method. Multiple response optimization was done through RSM. The optimum conditions of selected independent variables were 300 °C IR temperature, 21 mm heater to product spacing, and 120 seconds treatment time resulted in the 90.40% of peeling efficiency, 35 °C of rhizome surface temperature, 8.67% of color change, 0.56% volatile oil loss, and 11.53 kg of firmness. The comparison of optimized infrared assisted peeling was carried out with conventional abrasion and lye peeling methods based on their quality attributes. IR assisted dry-peeling results in minimum quality losses, higher peeling efficiency and feasible over conventional peeling methods of ginger rhizome. There was zero effluent generated during infrared assisted peeling of ginger rhizome. PRACTICAL APPLICATION: Peeling is one of the foremost mandatory unit operation for processing of all fruits, vegetables, and rhizomes like ginger. Presently, lye peeling is most widely used peeling method in industries followed by mechanical peeling. Both of these methods have serious issues like huge effluent generation (BOD) and water consumption which leads to the concern about environmental issues. Infrared dry peeling is the most prominent alternative for industries having the potential to deals with environmental issues. IR peeling method can be easily designed and scaled-up as per the specific requirment of industries. Therefore, understanding its feasibility for peeling of a most difficult commodity like ginger and understanding its insight into the quality of peeled product is need of the hour.

Hybrid 23/27 Gauge Vitrectomy - Combining the Charm of 27G with the Efficacy of 23G

Background

Minimally invasive transconjunctival sutureless vitrectomy (MIVS) has evolved into the standard of care, smaller incisions thought to result in lower ocular surface trauma and shorter times to recovery. The currently most relevant limitations in macular surgery may be light intensity and 27G instrument stability. Therefore, we thought to compare standard 23 and 27G vitrectomy with a hybrid technique using one 23G and two 27G ports regarding surgical times and short-term outcomes.

Methods

This retrospective comparison included 90 single-center consecutive cases of eyes undergoing elective micro-invasive vitrectomy for epiretinal membranes or idiopathic macular holes between October 2017 and June 2018. The main criteria for the comparison were total surgical time as primary outcome parameter and treatment-demanding intra- and postoperative complications along with recovery of best-corrected visual acuity (BCVA) and central retinal thickness (CRT) from prior to surgery to 1 month thereafter as secondary parameters as independent parameters for the recovery from the pre-existing pathology and the surgical trauma.

Results

Surgical times were shorter with 23G and 23/27G compared to 27G (23G: 38.4±13.1; 27G: 48.1±15.3; 23/27G: 34.9±9 mins; p=0.0005) with no differences in BCVA and CRT outcomes. Switching from 27G to a larger port size was not necessary in any instance. Cryotherapy was applied in 15%, 30%, and 22.5% to suspected retinal pathologies, beyond these, in 5%, 0%, and 7.5% for retinal tears. Four postoperative retinal detachments occurred (4.4%), one in the 23G and three in the 23/27G group requiring re-vitrectomy.

Conclusion

In this exploratory case series, 23/27G hybrid vitrectomy, combining the advantages of 23G and 27G techniques, resulted in shorter surgical times without evident disadvantages. The combination with cataract surgery was unproblematic.

Quantitative Assessment of Anti-Cancer Drug Efficacy From Coregistered Mass Spectrometry and Fluorescence Microscopy Images of Multicellular Tumor Spheroids

Spheroids-three-dimensional aggregates of cells grown from a cancer cell line-represent a model of living tissue for chemotherapy investigation. Distribution of chemotherapeutics in spheroid sections was determined using the matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI). Proliferating or apoptotic cells were immunohistochemically labeled and visualized by laser scanning confocal fluorescence microscopy (LSCM). Drug efficacy was evaluated by comparing coregistered MALDI MSI and LSCM data of drug-treated spheroids with LSCM only data of untreated control spheroids. We developed a fiducial-based workflow for coregistration of low-resolution MALDI MS with high-resolution LSCM images. To allow comparison of drug and cell distribution between the drug-treated and untreated spheroids of different shapes or diameters, we introduced a common diffusion-related coordinate, the distance from the spheroid boundary. In a procedure referred to as "peeling", we correlated average drug distribution at a certain distance with the average reduction in the affected cells between the untreated and the treated spheroids. This novel approach makes it possible to differentiate between peripheral cells that died due to therapy and the innermost cells which died naturally. Two novel algorithms-for MALDI MS image denoising and for weighting of MALDI MSI and LSCM data by the presence of cell nuclei-are also presented.

Dynamic biological adhesion: mechanisms for controlling attachment during locomotion

The rapid control of surface attachment is a key feature of natural adhesive systems used for locomotion, and a property highly desirable for man-made adhesives. Here, we describe the challenges of adhesion control and the timescales involved across diverse biological attachment systems and different adhesive mechanisms. The most widespread control principle for dynamic surface attachment in climbing animals is that adhesion is 'shear-sensitive' (directional): pulling adhesive pads towards the body results in strong attachment, whereas pushing them away from it leads to easy detachment, providing a rapid mechanical 'switch'. Shear-sensitivity is based on changes of contact area and adhesive strength, which in turn arise from non-adhesive default positions, the mechanics of peeling, pad sliding, and the targeted storage and controlled release of elastic strain energy. The control of adhesion via shear forces is deeply integrated with the climbing animals' anatomy and locomotion, and involves both active neuromuscular control, and rapid passive responses of sophisticated mechanical systems. The resulting dynamic adhesive systems are robust, reliable, versatile and nevertheless remarkably simple. This article is part of the theme issue 'Transdisciplinary approaches to the study of adhesion and adhesives in biological systems'.

Functional magnetic resonance imaging following epimacular and internal limiting membrane peeling - ipsilateral and contralateral findings

PURPOSE

The purpose of this study was to find out whether peeling of the epimacular membrane (EMM) and internal limiting membrane (ILM) for symptomatic lamellar macular hole (LMH), causes impairment of the visual cortex.

PATIENTS AND METHODS

This pilot study consisted of 8 eyes of 4 patients (2 females and 2 males), mean age 69.25 years (60-83 years), who underwent pars plana vitrectomy and EMM and ILM peeling in one eye for lamellar macular hole The second eye remained intact. The patients had no other ophthalmological or neurological disease. The control group consisted of 20 eyes of 10 healthy people (8 females and 2 males). mean age 52 years (34-65 years). In all of them, we performed functional magnetic resonance imaging (fMRI) of the brain to the visual paradigm (black and white chessboard of 25.8 x 16.2 degrees in size), as well as in patients 3-4 years following the surgery. For statistical processing, we used ANOVA and multiple regression for adjustment for the age of patients.

RESULTS

In all patients, we recorded a decrease in fMRI activity of the brain following stimulation of the eye in which surgical intervention was performed. The fMRI values using ANOVA (without adjustment for age) were significantly different between groups (P<0.001). Following adjustment for age and the use of multiple regression, the fMRI values in the operated eyes were lower by 4142.39 vs the control eyes. In the group of unoperated eyes, the fMRI values were lower by 2807.39 vs the control eyes. Therefore, the results did not differ very much from the results without adjustment.

CONCLUSION

In patients with symptomatic partial macular defect following EMM and ILM peeling, we recorded a significant decrease of the fMRI activity of the brain following stimulation of the operated eye, compared to the control group. We also found a decrease in activity in fMRI following stimulation of the contralateral eye. These findings lead us to the conclusion that EMM and ILM peeling may cause secondary impairment of the visual centres in the brain, not only on the side of the surgical intervention, but also on the contralateral side.

Ethylene facilitates boil-peeling in fruits

Boil-peeling is a common method of cooking or processing some horticultural crops. While boil-peeling is possible in some horticultural crops, a comprehensive list of crops for which boil-peeling is possible does not exist. According to a previous study, ethylene facilitates boil-peeling of kiwifruits. Thus, we studied the effect of ethylene treatment on boil-peeling in the kiwifruit variety "Rainbow red." We found that with increasing ethylene concentration in the fruits, boil-peeling success of kiwifruits increased. In the no-ethylene treatment, flesh firmness of the fruits decreased and boil-peeling could not be carried out successfully. Thus, it was clear that ethylene facilitates boil-peeling in kiwifruit. Furthermore, boil-peeling was possible after ethylene treatment in persimmon and Japanese pear, which had proved to be impossible so far. Kiwifruits, persimmon, and Japanese pear were classified as climacteric fruits that react with high ethylene sensitivity. Thus, ethylene may facilitate boil-peeling in climacteric fruits. This finding can possibly suggest new application for ethylene during fruit processing or in processed fruits.

Characterization of Soaking Process' Impact in Common Beans Phenolic Composition: Contribute from the Unexplored Portuguese Germplasm

Despite the common beans' nutritional and phytochemical value, in Portugal its consumption decreased more than 50% in the last decade. The present study aimed to characterize phenolic composition of the Portuguese traditional varieties and corresponding soaked seed fractions (including soaking water). With such purpose, the phenolic composition (total content of soluble phenolics, flavonoids, and proanthocyanidins) and in vitro antioxidant activity were evaluated in the raw whole flour of 31 Portuguese common bean varieties. The phenolic composition of the soaked fractions was respectively compared to the raw flour. Phenolic compounds' identification and relative quantification were achieved by UPLC-TripleTOF-MS for one representative variety and their fractions. The highest phenolic content was found in colored varieties and the brown market class highlighted as the richest one. The loss of phenolic compounds to the soaking water was highly dependent on variety. The predominant phenolic compounds' classes were flavan-3-ols (soaking water and coats), flavonols (coats), and phenolic acids (cotyledons). This characterization study showed the diversity on the phenolic composition of Portuguese varieties and the need to adjust the soaking and peeling processes to the variety (considering the possible loss of potential health promoter compounds, e.g., phenolic compounds).

Adhesion Strength and Rolling Properties of Descemet Membrane Endothelial Keratoplasty Grafts in a Rabbit Eye Model

Purpose: To investigate the optimal time for Descemet membrane endothelial keratoplasty (DMEK) graft peeling, and to analyze the rolling properties of endothelial denuded grafts in a rabbit eye model. Materials and Methods: The vertical peeling force required to peel 1 mm wide Descemet membrane (DM) strips, was measured as the change in weight of the system during force application in a rabbit model. Twenty-one rabbit corneoscleral rims were stored in phosphate-buffered saline (PBS) at 4°C, and force analysis was performed at days 1, 5, or 21 after harvesting. After half of the strips of day 5 corneas were peeled and analyzed, the rims were moved to Optisol GS at 4°C, and the remaining strips were peeled off for force analysis at day 10. Separate DM grafts (n = 7) were analyzed by intraoperative optical coherence tomography (OCT) to determine the tissue rolling diameter before and after removal of endothelial cells by a swab. Unpaired t-test was used for statistical analysis. Results: There was a decrease in DM peeling force (p = .008) between days 1 and 5 (556.04 ± 111.76 and 324.30 ± 96.4 mg, respectively), and no difference between days 5 and 21 (p = .53). Peeling force for day 5 corneas placed in Optisol was higher at day 10 (324.30 ± 96.4 to 669.92 ± 166.24 mg, p = .005). The average rolling diameter of DM grafts was similar before and after the removal of endothelial cells (257.9 ± 131.1 and 249.8 ± 126.6 μm, respectively). Conclusions: DMEK Graft procurement could be potentially facilitated by lower DM-stromal adhesion strength at day five after obtaining corneoscleral rims, in a rabbit eye model. Time in the storage medium may influence adhesion strength. Endothelial cells do not appear to play a significant role in the rolling diameter of DM grafts.

Three-dimensional printing spiders: back-and-forth glue application yields silk anchorages with high pull-off resistance under varying loading situations

The anchorage of structures is a crucial element of construction, both for humans and animals. Spiders use adhesive plaques to attach silk threads to substrates. Both biological and artificial adhesive structures usually have an optimal loading angle, and are prone to varying loading situations. Silk anchorages, however, must cope with loading in highly variable directions. Here we show that the detachment forces of thread anchorages of orb-web spiders are highly robust against pulling in different directions. This is gained by a two-step back-and-forth spinning pattern during the rapid production of the adhesive plaque, which shifts the thread insertion point towards the plaque centre and forms a flexible tree root-like network of branching fibres around the loading point. Using a morphometric approach and a tape-and-thread model we show that neither area, nor width of the plaque, but the shift of the loading point towards the plaque centre has the highest effect on pull-off resistance. This is explained by a circular propagation of the delamination crack with a low peeling angle. We further show that silken attachment discs are highly directional and adjusted to provide maximal performance in the upstream dragline. These results show that the way the glue is applied, crucially enhances the toughness of the anchorage without the need of additional material intake. This work is a starting point to study the evolution of tough and universal thread anchorages among spiders, and to develop bioinspired 'instant' anchorages of thread- and cable-like structures to a broad bandwidth of substrates.

On the Material Characterisation of Wind Turbine Blade Coatings: The Effect of Interphase Coating-Laminate Adhesion on Rain Erosion Performance

Rain erosion damage, caused by repeated droplet impact on wind turbine blades, is a major cause for concern, even more so at offshore locations with larger blades and higher tip speeds. Due to the negative economic influence of blade erosion, all wind turbine Original Equipment Manufacturers (OEMs) are actively seeking solutions. In most cases, since the surface coating plays a decisive role in the blade manufacture and overall performance, it has been identified as an area where a solution may be obtained. In this research, two main coating technologies have been considered: In-mould coatings (Gel coating) applied during moulding on the entire blade surface and the post-mould coatings specifically developed for Leading Edge Protection (LEP). The coating adhesion and erosion is affected by the shock waves created by the collapsing water droplets on impact. The stress waves are reflected and transmitted to the laminate substrate, so microstructural discontinuities in coating layers and interfaces play a key role on its degradation and may accelerate erosion by delamination. Analytical and numerical models are commonly used to relate lifetime prediction and to identify suitable coating and composite substrate combinations based on their potential stress reduction on the interface. Nevertheless, in order to use them, it is necessary to measure the contact adhesion resistance of the multi-layered system interfaces. The rain erosion performance is assessed using an accelerated testing technique, whereby the test material is repeatedly impacted at high speed with water droplets in a Whirling Arm Rain Erosion Rig (WARER). The materials, specifically the coating–laminate interphase region and acoustic properties, are further characterised by several laboratory tests, including Differential Scanning Calorimetry (DSC), pull-off testing, peeling–adhesion testing and nanoindentation testing. This body of work includes a number of case studies. The first case study compares two of the main coating technologies used in industry (i.e., gel coating and LEP); the second case investigates the effects of the in-mould gel coating curing; and the third considers the inclusion of a primer layer on a LEP configuration system. Following these case studies, the LEP is found to be a far superior coating due to its appropriate mechanical and acoustic properties and the interface between the coating and the substrate is highlighted as a key aspect, as poor adhesion can lead to delamination and, ultimately, premature failure of the coating.

Efficacy of peeling during different periods of the menstrual cycle on acne

BACKGROUND AND DESIGN

The aim of this study was to investigate the efficacy of 50% glycolic acid peeling performed at different phases of menstruation on acne.

MATERIALS AND METHODS

This study included 30 patients with mild-to-moderate acne. Those with regular menstrual cycles and no history or laboratory evidence of hormonal pathology, hirsutism were selected. Thirty patients were divided in three groups. The first group received peeling applications in the first 7 days of menstruation; the second group received the peel between 10 and 14 days; and the third group received the peel during the last 10 days of menstruation.

RESULTS

The 30 female patients included in study. All patients' menstrual cycles were regular. All groups were homogenous in terms of initial acne severity scores. Acne severity scores decreased in all groups after 3 months of therapy; statistically significant differences were achieved only in the second group.

DISCUSSION

The results of our study suggest that chemical peeling administered during ovulation provides the most significant benefit for acne lesions. Ovulation is the period when estrogen reaches its highest level. Estrogen decreases sebum production through different mechanisms. The beneficial effects of estrogen on acne and healing in combination with those of chemical peeling may cause synergistic therapeutic effects with pronounced results.

A systematic review of treatments for acne scarring. Part 1: Non-energy-based techniques

Acne is a common condition that can result in permanent scarring. We have performed a comprehensive literature search of the last 10 years in order to determine the efficacy and side effects of commonly used treatments against post-acne scarring. A total of 36 relevant articles were identified on the following interventions: subcision (10), dermabrasion (one), microneedling (eight), dermal fillers (five), and chemical peeling (12). Post acne scarring is a common and challenging condition with no easy and definitive solution. The above interventions have been used with varying degrees of efficacy, each having both pros and cons. All have been deemed to be safe with few and transient adverse reactions. However, further trials with larger number of patients are necessary in order to reach more concrete conclusions regarding their efficacy.

Palmoplantar exfoliation due to chloroquine

Chloroquine is the drug very frequently used for the treatment of malaria. It is also used in amebiasis, rheumatoid arthritis, and various dermatological conditions. Chloroquine can cause muscle problems, loss of appetite, and diarrhea as a side effect. Cutaneous toxicity includes pruritus, hair loss, photosensitivity, and color changes. Exfoliation of skin over palms and soles is caused by chemotherapeutic drugs such as axitinib, fluorouracil, idarubicin, doxorubicin, sunitinib, sorafenib, and paclitaxel. Here, a case of a 40-year-old female is presented who developed palmoplantar exfoliation with depigmentation after taking chloroquine. Although not life-threatening, this side effect of a commonly used drug may cause anxiety and functional impairment which in turn affects the quality of life of an individual.

Comparison the effectiveness of pyruvic acid 50% and salicylic acid 30% in the treatment of acne

BACKGROUND

Acne vulgaris is a chronic inflammatory disease of the pilosebaceous follicles and one of the most common skin diseases. The peeling method has been recently found to be effective for acne treatment. This study aimed to compare the efficacy of pyruvic acid 50% and salicylic acid 30% peeling in the treatment of mild to moderate acne.

MATERIALS AND METHODS

In a prospective single-blinded clinical trial, 86 patients with acne were randomly assigned into two groups. In both groups, the routine treatment of acne (topical solution of erythromycin 4%, triclorocarban soap, and sunscreen) were used twice a day for 8 weeks. In addition, salicylic acid 30% for the control group and pyruvic acid 50% for the case group were used. In both groups, acne severity index (ASI) was calculated before and at week 2, 4, 6, and 8 of the treatment. Patient satisfaction was assessed at the end of the treatment. Side effects were recorded using a checklist.

RESULTS

In both groups, the reduction in the number of comedones, papules, and ASI were statistically significant (P < 0.001) in the course of treatment. However, it was not significant regarding the number of pustules (P = 0.09). None of the number of comedone, papules, pustules, and ASI was statistically different between study groups. Both treatment groups had similar side effects except for scaling in the fifth session, which was significantly lower in salicylic acid - treated patients (P = 0.015).

CONCLUSION

Both pyruvic acid 50% and salicylic acid 30% are effective in the improvement of mild to moderate acne with no significant difference in efficacy and side effects.

The speed of an inclined ruck

Steady rucks in an elastic beam can roll at constant speed down an inclined plane. We examine the dynamics of these travelling-wave structures and argue that their speed can be dictated by a combination of the physical conditions arising in the vicinity of the 'contact points' where the beam is peeled off the underlying plane and stuck back down. We provide three detailed models for the contact dynamics: viscoelastic fracture, a thermodynamic model for bond formation and detachment and adhesion mediated by a thin liquid film. The results are compared with experiments.

Melasma update

Melasma is an acquired pigmentary disorder characterized by symmetrical hyperpigmented macules on the face. Its pathogenesis is complex and involves the interplay of various factors such as genetic predisposition, ultraviolet radiation, hormonal factors, and drugs. An insight into the pathogenesis is important to devise treatment modalities that accurately target the disease process and prevent relapses. Hydroquinone remains the gold standard of treatment though many newer drugs, especially plant extracts, have been developed in the last few years. In this article, we review the pathogenetic factors involved in melasma. We also describe the newer treatment options available and their efficacy. We carried out a PubMed search using the following terms “melasma, pathogenesis, etiology, diagnosis, treatment” and have included data of the last few years.

Palmoplantar peeling secondary to sirolimus therapy

Sirolimus (rapamycin) is an immunosuppressive agent commonly used in transplant recipients. Although sirolimus has less renal toxicity than calcineurin inhibitors, its use has been limited by its side effects. The most common cutaneous pathologies associated with sirolimus are inflammatory acneiform eruptions, lymphedema and aphthous ulcers. We present a novel cutaneous manifestation of sirolimus therapy that limited its use in at least one transplant recipient. Upon commencing sirolimus therapy, four solid organ transplant recipients developed tender, nonpruritic palmoplantar peeling within the first month of therapy. The peeling clinically resembled a mild form of hand-foot syndrome, yet none of the patients had been treated with chemotherapeutics. Desquamation presented on the palms and soles with dry vesicles and minor peeling extending to the dorsal aspects of the hands and feet. Histologically, the lesions were noninflammatory; the epidermis showed subtle separation between keratinocytes, suggesting either spongiosis or a defect in intercellular adhesion. One patient opted to discontinue treatment because of the tenderness associated with the palmoplantar peeling, which resulted in complete resolution within 2 weeks.

Integrating genealogical and dynamical modelling to infer escape and reversion rates in HIV epitopes

The rates of escape and reversion in response to selection pressure arising from the host immune system, notably the cytotoxic T-lymphocyte (CTL) response, are key factors determining the evolution of HIV. Existing methods for estimating these parameters from cross-sectional population data using ordinary differential equations (ODEs) ignore information about the genealogy of sampled HIV sequences, which has the potential to cause systematic bias and overestimate certainty. Here, we describe an integrated approach, validated through extensive simulations, which combines genealogical inference and epidemiological modelling, to estimate rates of CTL escape and reversion in HIV epitopes. We show that there is substantial uncertainty about rates of viral escape and reversion from cross-sectional data, which arises from the inherent stochasticity in the evolutionary process. By application to empirical data, we find that point estimates of rates from a previously published ODE model and the integrated approach presented here are often similar, but can also differ several-fold depending on the structure of the genealogy. The model-based approach we apply provides a framework for the statistical analysis and hypothesis testing of escape and reversion in population data and highlights the need for longitudinal and denser cross-sectional sampling to enable accurate estimate of these key parameters.

Skin anti-aging strategies

Skin aging is a complex biological process influenced by a combination of endogenous or intrinsic and exogenous or extrinsic factors. Because of the fact that skin health and beauty is considered one of the principal factors representing overall "well-being" and the perception of "health" in humans, several anti-aging strategies have been developed during the last years. It is the intention of this article to review the most important anti-aging strategies that dermatologists have nowadays in hand, including including preventive measurements, cosmetological strategies, topical and systemic therapeutic agents and invasive procedures.

A note on exact image reconstruction from a limited number of projections

In a recent paper in this journal by Kesidis and Papamarkos "A new method for the exact reconstruction of any gray-scale image from its projections is proposed." In this note we point out that this method is a special case of a well-known approach (peeling) and that it can produce exact reconstructions only under assumptions that are not realistic for practical methods of data collection. Further, we point out that some statements made in the paper regarding disadvantages of the algebraic reconstruction techniques (ART) as compared to the method of the paper are false.

Sampling genotypes in large pedigrees with loops

Markov chain Monte Carlo (MCMC) methods have been proposed to overcome computational problems in linkage and segregation analyses. This approach involves sampling genotypes at the marker and trait loci. Scalar-Gibbs is easy to implement, and it is widely used in genetics. However, the Markov chain that corresponds to scalar-Gibbs may not be irreducible when the marker locus has more than two alleles, and even when the chain is irreducible, mixing has been observed to be slow. These problems do not arise if the genotypes are sampled jointly from the entire pedigree. This paper proposes a method to jointly sample genotypes. The method combines the Elston-Stewart algorithm and iterative peeling, and is called the ESIP sampler. For a hypothetical pedigree, genotype probabilities are estimated from samples obtained using ESIP and also scalar-Gibbs. Approximate probabilities were also obtained by iterative peeling. Comparisons of these with exact genotypic probabilities obtained by the Elston-Stewart algorithm showed that ESIP and iterative peeling yielded genotypic probabilities that were very close to the exact values. Nevertheless, estimated probabilities from scalar-Gibbs with a chain of length 235 000, including a burn-in of 200 000 steps, were less accurate than probabilities estimated using ESIP with a chain of length 10 000, with a burn-in of 5 000 steps. The effective chain size (ECS) was estimated from the last 25 000 elements of the chain of length 125 000. For one of the ESIP samplers, the ECS ranged from 21 579 to 22 741, while for the scalar-Gibbs sampler, the ECS ranged from 64 to 671. Genotype probabilities were also estimated for a large real pedigree consisting of 3 223 individuals. For this pedigree, it is not feasible to obtain exact genotype probabilities by the Elston-Stewart algorithm. ESIP and iterative peeling yielded very similar results. However, results from scalar-Gibbs were less accurate.