Irregular Honeycomb Research Articles

Vitiligo Treated with Combined Piperine-Based Topical Treatment and Narrowband Ultraviolet B Therapy: Follow-Up with Reflectance Confocal Microscopy.

Reflectance confocal microscopy (RCM) has a defined in vivo morphology of vitiligo and re-pigmentation. Combination therapies seem more effective than monotherapies. We aim to describe the clinical and RCM features of re-pigmentation with combined narrowband ultraviolet B (NB-UVB) and piperine-based topical treatment in localized vitiligo. Eight patients enrolled at a single center received combined treatment: topical treatment was applied twice daily + NB-UVB twice weekly for 2 × 2-month periods. Clinical changes were analyzed by the Vitiligo Noticeability Scale (VNS) and percentage of re-pigmentation. The evaluator agreement was assessed. Predefined RCM features had the presence/absence of (i) blood vessels, (ii) dendritic cells, and the quantity of (i) an irregular honeycombed pattern and (ii) non-pigmented papillae. Clinical and RCM monitoring was performed at the baseline, 2, 3, 5, and 7 months. Macules were "slightly less noticeable" with 25-50% re-pigmentation. Irregular honeycomb patterns and non-pigmented papillae were significantly less frequently observed, and in less extended areas (T1 vs. T2, p = 0.039; T0 vs. T1, p = 0.005 and T2 vs. T4, p = 0.033). Dendritic cells and blood vessels improved, with significant changes in blood vessels (T1 vs. T2, p = 0.005 and T3 vs. T4, p = 0.008). RCM confirms the morphological changes induced by combined treatment for localized vitiligo.

Development of low‐fat Mozzarella cheeses enriched with soy or pea protein hydrolysates: Composition, texture and functional properties during ageing

To explore the effect of plant protein hydrolysate (PPHS, soy and pea protein hydrolysate) on the characteristics of low‐fat Mozzarella cheeses (LFCs), samples incorporating PPHS were prepared and analysed for pizza bake performance, texture, meltability, sensory attributes and microstructure. Upon addition of an appropriate amount of PPHS to cheese milk, the pizza bake performance, stretch performance and sensory properties of LFC were improved, while the texture values (hardness, stickiness and stretch force) decreased gradually. Cheese matrix exhibited an irregular honeycomb structure as the PPHS content increased. Therefore, PPHS holds promise as substitute for milk protein, and LFC containing PPHS represents a highly promising low‐fat dairy product with improved quality and diversified ingredients.

Development of ultra-broadband sound absorber based on double-layered irregular honeycomb microperforated panel

In this study, a broadband sound absorber was developed using a double-layered irregular honeycomb microperforated panel (MPP) structure and a particle swarm optimization (PSO) algorithm to address the issue of broadband sound absorption of MPPs. An acoustic impedance model of the designed sound absorber and an optimization algorithm were implemented to obtain the structural configuration parameters for quasi-perfect sound absorption. The coupling effect between the resonant elements and the optimized structural configuration parameters enabled broadband and high-efficiency sound absorption. The impedance tube experimental results demonstrated an excellent broadband sound absorption level within the range of linear acoustics, and the designed triad and tetrad structures exhibited more than 70% absorption efficiency in the range of 609–4 002 Hz and 518–5 162 Hz, respectively. This study provides a design method and insights into the design, promotion, and application of broadband sound absorbers.

From pencils to pineapples: finding honeycombs everywhere

Software tool analyzes large datasets to identify regular and irregular honeycomb structures.

Combining mechanisms of black carbon and magnetic minerals in power plant fly ash

Black carbon (BC), one of the pollutants emitted from fossil fuel combustion, is closely associated with minerals and other hazardous substances. To date, little is known about the mechanisms between BC and magnetic minerals. Accordingly, further investigating the association between magnetic minerals and BC is necessary. In this work, the extraction of BC from fly ash and the magnetic fraction from BC was achieved by flotation and magnetic separation, respectively. The morphology, mineralogical composition, and magnetic properties of BC and magnetic fraction were characterized by FTIR, XRD, SEM-EDS, and vibrating sample magnetometer (VSM). The results show that BC and magnetic minerals have similar mineral compositions, rich in quartz, mullite, magnetite, and hematite. The magnetic minerals have prominent spherical characteristics and are distributed on the surface and inside the pores of BC with irregular honeycomb features. The VSM and XRD analyses show that Fe3O4 is the primary magnetic material. Moreover, large amounts of C, O, and Fe around and on the surface of magnetic spheres were detected by EDS, indicating that the spherical particles may be the structure of BC-coated Fe3O4. Pyrolysis experiments showed that the yield of the magnetic fraction in the pyrolysis product reached 60 %, far exceeding the theoretical yield of 12 % based on 5 % of doped Fe. This further proves that Fe3O4 was combined with a large number of organics during its formation, which may be due to coating and chemical adsorption. Quantum chemical calculations also confirmed this chemical adsorption between Fe3O4 with BC based on density flooding theory, in which adsorption energies ranged from −213.374 KJ/mol to −827.741 KJ/mol.

The Challenges in Investigating the Pathogenesis of Sensitive Skin by Noninvasive Measurements: A Systematic Review.

Sensitive skin (SS) is a common cutaneous condition that seriously affects people's quality of life, but studies of sensitive skin pathogenesis are unclear, the exploration are ongoing, and the biophysical properties of sensitive skin disagree with the study results. In this paper, we summarize the noninvasive biophysical and imaging instrumental methods used for sensitive skin and provide support for the classification of sensitive skin subtypes to prescribe precise treatment. PubMed and Web of Science databases were searched according to PRISMA guidelines for articles from January 1971 to May 2022 that used noninvasive biophysical or imaging methods to monitor adult subjects with sensitive skin. The quality of the included articles was determined based on 22 items of the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement. A total of 55 studies were included, representing 8 biophysical and 5 imaging methods and their applications in treatment efficacy evaluation studies. The biophysical parameter and cutaneous morphological property changes in sensitive skin subjects were observed. The quality of the studies was relatively low, and there was high variability in results between studies. Several parameters have shown tremendous potential in exploring the pathogenesis with different sensitive skin subtypes: type I may be detected with higher transepidermal water loss and lower stratum corneum hydration values, as well as with thinner epidermis with a shallower and more irregular honeycomb structure; Type II and III are more prone to higher blood flow, lower current perception threshold than normal skin. This systematic review identifies key reasons for the lack of uniform trends in noninvasive measurements and recommends the use of effective selection instruments or relevant parameters to explore the pathogenesis of sensitive skin, and to differentiate the subtypes of sensitive skin for achieving the precise treatment.

Skin ageing: Clinical aspects and in vivo microscopic patterns observed with reflectance confocal microscopy and optical coherence tomography.

Few studies have combined high-resolution, non-invasive imaging, such as standardized clinical images, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT), for age-related skin change characterization according to age groups. This study aimed to correlate clinical manifestations of ageing with skin cytoarchitectural background observed with high-resolution, non-invasive imaging according to age-related skin pattern distribution. A set of 140 non-pathological facial skin images were retrospectively retrieved from a research database. Subjects, aged between 20 and 89, were divided into 7 age groups. Clinical features were explored with VISIA, including hyperpigmentation, skin texture, wrinkles, pores and red areas, quantified and expressed as automated absolute scores. Previously described RCM and OCT epidermal and dermal features associated with ageing were investigated. All features were assessed for distribution and correlation among age groups. Significant direct correlations between age and clinical features were proven for cutaneous hyperpigmentation, skin texture, wrinkles and red areas. As age advances, RCM epidermal irregular honeycomb and mottled pigmentation are more frequently observed and collagen is more frequently coarse, huddled and curled, while the epidermis in OCT is thickened and the dermal density is decreased with more disrupted collagen fibres. RCM and OCT feature changes correlate directly and indirectly as well as correlating directly and indirectly with standardized clinical images. Clinical manifestations of ageing correlate with skin cytoarchitectural background observed with RCM and OCT. In conclusion, complimentary information between standardized clinical images and high-resolution, non-invasive imaging will assist in the development of future studies dedicated to skin ageing assessment and treatment effectiveness.

Fractional correlated insulating states at one-third filled magic angle twisted bilayer graphene

The observation of superconductivity and correlated insulating states in twisted bilayer graphene has motivated much theoretical progress at integer fillings. However, little attention has been given to fractional fillings. Here we show that the three-peak structure of Wannier orbitals, dictated by the symmetry and topology of flat bands, facilitates the emergence of a state we name a “fractional correlated insulator” at commensurate fractional filling of ν = n ± 1/3. Specifically for the filling of 1/3 electrons per moiré unit cell, we show that short-range interactions lead to an extensive entropy due to the “breathing” degree of freedom of an irregular honeycomb lattice that emerges through defect lines. The leading further-range interaction lifts this degeneracy and selects a ferromagnetic nematic state that breaks AB/BA sublattice symmetry. The proposed fractional correlated insulating state might underlie the suppression of superconductivity at ν = 2 − 1/3 filling observed in ref. 1.

Water saturation effects on the mechanical characteristics and fracture evolution of sandstone containing pre-existing flaws

To comprehensively investigate the effect of water content on the crack propagation characteristics and fracture mechanism of jointed rock, uniaxial compression experiments were conducted on red sandstone specimens under different water content conditions and different bridge lengths. Acoustic emission (AE) techniques and digital image correlation (DIC) methods were applied to record the AE signals and deformation field of the specimens during the testing. The physical and mechanical properties, crack propagation characteristics and AE parameters of red sandstone under water–rock coupling were analysed. The results demonstrated that the water content and rock bridge length have conspicuous effects on the compressive strength, elastic modulus, temporal b value, P-wave velocity, and crack propagation model. The fracture initiates from the lowest pre-fabricated crack and the fracture mode gradually changes from shear to tensile fracture with the increase of the rock bridge length. Additionally, the micro-structure of the sandstone develops from a relatively dense pore cement structure to an irregular honeycomb structure. And the deterioration of the rock strength parameters could refer to the pore pressure generated by free water.

An FFT-based method for uncertainty quantification of Nomex honeycomb’s in-plane elastic properties

The honeycomb manufacturing process involves complex and inter-related procedures spanning multiple physics domains and scales. The geometry heterogeneity in honeycomb cells inevitably exists and propagates to the uncertainty of the honeycomb’s mechanical performance. Quantitatively characterizing the effect of cell geometry variability on the effective mechanical properties of honeycomb hence becomes critically important. In this study, a Fast Fourier Transform (FFT) based method was developed to predict the effective in-plane elastic properties of irregular hexagonal honeycomb. The honeycomb geometry heterogeneity was identified with a digital image technology by examining a large number of cells. Correlation analysis on the resulting statistical data enables determining the interdependence of cell wall lengths and angles. Using a Representative Unit Cell (RUC) with varying cell wall lengths and angles, an analytical function for the effective in-plane elastic parameters was established by incorporating the dependencies. The statistical quantification of cell geometry and the propagation of RUC’s elastic characteristics were further integrated into the FFT-based multiscale framework for predicting the in-plane elastic moduli of irregular honeycomb. The tensile and shear tests on the irregular honeycombs, together with the corresponding finite element analysis, were used to verify the proposed method. Both experimental and numerical results confirmed that the uncertainty of elastic moduli achieved by the FFT-based method provides a reasonable estimation.

Study on the evolution pattern of the chemical structure of Fenton pretreated lignin during hydrothermal carbonization

Two new lignin feedstocks (HLF and DALF) were obtained by Fenton pretreatment of herbal lignin (HL) and de-alkalized lignin (DAL), and hydrothermal carbonization of each lignin sample was carried out at 290 °C with different holding times to investigate the impact of Fenton pretreatment on the physicochemical properties of the hydrothermal materials. The analyses based on 13C solid-state NMR, XPS, FTIR, SEM and fully automated calorimetry showed that the optimal holding time for hydrothermal carbonization of lignin at 290 °C was 30 min. The two types of lignin were treated with Fenton pretreatment to remove some methoxy groups and make the aromatic structural units more compact. Hydrothermal carbonization removed a small amount of αO4 and βO4 bonds from the structure, increased the guaiacyl units [G], decreased the syringyl units [S], and formed more stable 4-O-5 and CC bonds, which in turn polymerized into 10–300 µm irregular spherical carbon particles or porous honeycomb carbon blocks. The calorific values of HLF290-30 and DALF290-30 were increased to 31.04 MJ/kg and 32.17 MJ/kg, respectively, by the combination of Fenton pretreatment and hydrothermal carbonization. Overall, the Fenton pretreatment of lignin enhanced the degree of aromatization and removal of methoxylation during hydrothermal carbonization of lignin. This study provides a sustainable and green strategy for the preparation of high calorific value hydrochar as well as all-round utilization of lignin.

Biochar derived from non-customized matamba fruit shell as an adsorbent for wastewater treatment

This study of Matamba shell reviled them as material with outstanding surface morphology, elemental and kinetic mechanism characteristics. Mutamba biochar revealed irregular honeycomb morphological transformation from the field emission scanning electron microscope after pyrolysis at 600 °C for 2 h. Energy dispersive X-ray spectroscopy revealed high content of carbon (72.68wt%), nitrogen (14.14wt%) and oxygen (10.35wt%) on the biochar surface. The available oxygen composition provides enough polarization ability for high iodine adsorption (43.65 mmol/g) from the experimental data which were significantly induced by weak van der Waals forces and π-π and π-stacking interaction on the biochar surface and its micropores. The carbon content above 50% in ash rich biochar with an increase in pyrolysis can be ascribed to elements incorporated into aromatic or heterocyclic ring system established through preferential loss of oxygen at 600 °C pyrolysis. The adsorption kinetics were conducted to evaluate the equilibrium adsorption of the novel material and Elovich and Intra particle diffusion better described well the kinetic adsorption through Iodine adsorption than pseudo first order and pseudo second order models. Elovich was the best model to fit the adsorption kinetics with 45.41 mmol/(g•min) adsorption rate. The second order Akaike Information Criterion (38.26), adjusted correlation coefficient R 2 (0.9898) and sum of squares error (1.442) were used to fit the data. Consequently, the biochar in this study can serve as a promising green material for efficiently removing organic and inorganic contaminants from the environmental water ecosystem. The environmental significance of biochar will be of fundamental meaning to rural areas in developing countries in aquatic contaminants immobilization for water reuse. These results indicate that the Matamba fruit shells has the possibility to be used as an eco-friendly and low-cost effective adsorbent for anionic dye removal from the water environment. They also demonstrate the immense potential of the fruit shell waste to produce high performance biochar as an alternative green carbonaceous material that can be applied to adsorb organic and inorganic unwanted constituencies from wastewater as well as improvement of waste management in developing countries at a low cost. Its application as a pathway mitigation for diminishing greenhouse gasses and reducing the global warming potential could not be underestimated.

Research on structure and antioxidant activity of polysaccharides from Ginkgo biloba leaves

Ginkgo biloba extract is regarded as one of the most popular natural plant preparations, among which polysaccharide is considered to be an important functional factor. In the study, polysaccharide was extracted from Ginkgo biloba leaves powder by ultrasonic-enzyme assisted water-soluble alcohol precipitation. The content of crude polysaccharide was 82.4% by the phenol sulfuric acid method. Structure and chemical composition of Ginkgo biloba leaves polysaccharide were investigated by chromatographic and nuclear magnetic resonance spectoscocopy analyses. Results showed that the purified Ginkgo biloba leaves polysaccharide was an acidic polysaccharide with a molecular weight of 12.08 kDa, containing glycosidic linkages of β-D-Rhap-(1→, β-L-Xylp-(1→, →4)-β-D-Manp-(1→, →4)-β-D-Glcp-(1→, →6)-β-D-Manp-(1→, →3)-β-L-Araf-(1→, →4)-β-D-Galp-(1→, →3,4)-β-D-Glcp-(1→. The monosaccharides were composed of rhamnose, arabinose, xylose, mannose, glucose and galactose with a molar ratio of 5.56:3.84:2.34:7.54:8.34:1, respectively. Scanning electron microscopy analysis showed that the microscopic conformation of the purified Ginkgo biloba leaves polysaccharide was fluffy and irregular honeycomb with certain pores. Antioxidant activities in vitro, including scavenging 1,1-Diphenyl-2-picrylhydrazine, scavenging hydroxyl radical activity and scavenging superoxide anion were 78.8%, 79.2% and 43.7%, respectively, which suggested that the purified Ginkgo biloba leaves polysaccharide had strong antioxidant activities. These findings indicate that Ginkgo. biloba leaves polysaccharides have potential as natural antioxidants in food processing.

Closed-form representation for equivalent electromagnetic parameters of irregular hexagonal honeycomb radar-absorbing materials

In this study, a new closed-form expression is developed to determine the equivalent electromagnetic parameters (permittivity and permeability) of biaxial anisotropic honeycomb radar-absorbing materials (RAMs). Based on the equivalent medium theory, the nonmagnetic substrate and absorbing coating of the honeycomb structure are equivalent to one kind of material, and then, the effective electromagnetic properties of irregular hexagonal (compressed or stretched) honeycombs are obtained by using the layered anisotropic model. In order to validate the effectiveness and correctness of this new closed-form expression, experimental tests and numerical simulation are adopted. The results show good agreement among the experimental tests, numerical simulation, and theoretical analysis within the specified frequency range (2–18 GHz), which confirms the validly of the proposed new method. Compared with the previous layered anisotropic model, the modified new model is more accurate for irregular hexagonal honeycomb RAMs. Furthermore, it can predict the effective permittivity (permeability) precisely without experimental measurements or numerical simulation, and it is of great significance for the design of honeycomb RAMs.

Carboxyl-functionalized mesoporous silica nanoparticles for the controlled delivery of poorly water-soluble non-steroidal anti-inflammatory drugs

The purpose of this study was to investigate the delivery of poorly water-soluble non-steroidal anti-inflammatory drugs (NSAIDs) by carboxyl-functionalized mesoporous silica nanoparticles (MSN-COOH) with high specific surface area (SBET). In this study, MSN-COOH was prepared by collaborative self-assembly using cetyltrimethylammonium bromide (CTAB) as template and hydrolysis (3-triethoxyl-propyl) succinic anhydride (TESPSA) as co-structure auxiliary directing agent (CSDA). The drug delivery systems were constructed with NSAIDs including Nimesulide (NMS) and Indomethacin (IMC) as model drugs. Moreover, the characterization techniques, hemolysis and bio-adsorption testes, in vitro drug release and in vivo biological studies of MSN-COOH were also carried out. The characterization results showed that MSN-COOH is spheres with clearly visible irregular honeycomb nanopores and rough surface (SBET: 1257 m2/g, pore volume (VP): 1.17 cm3/g). After loading NMS/IMC into MSN-COOH with high drug loading efficiency (NMS: 98.7 and IMC: 98.2%), most crystalline NMS and IMC converted to amorphous phase confirmed using differential scanning calorimeter (DSC) and X-ray power diffraction (XRD) analysis. Meanwhile, MSN-COOH significantly increased the dissolution of NMS and IMC compared with non-functionalized mesoporous silica nanoparticles (MSN), which was also confirmed by wettability experiments. The results of in vivo biological effects showed that MSN-COOH had higher bioavailability of NMS and IMC than MSN, and exerted strong anti-inflammatory effects by delivering more NMS and IMC in vivo. Statement of significanceThis study successfully prepared MSNs-COOH (mesoporous silica nanoparticles modified with negatively charged carboxyl groups on the surface and in the pores) with high specific surface area and pore volume by using the negatively charged carboxyl group (hyd-TESPSA) and the positively charged CTAB self-assembled through electrostatic attraction under alkaline conditions. The drug delivery systems were constructed with Nimesulide (NMS) and Indomethacin (IMC) as model drugs. The results showed MSNs-COOH had high drug loading capacity and also exhibited good in vitro drug release properties. Interestingly, NMS loaded MSNs-COOH also had a potential pH responsive release effect. In vivo biological studies revealed that NMS/IMC loaded MSNs-COOH could evidently improve the bioavailability and played the strong anti-inflammatory effects.

Effect of Axial Deformation on Elastic Properties of Irregular Honeycomb Structure

Irregular honeycomb structures occur abundantly in nature and in man-made products, and are an active area of research. In this paper, according to the optimization of regular honeycomb structures, two types of irregular honeycomb structures with both positive and negative Poisson’s ratios are presented. The elastic properties of irregular honeycombs with varying structure angles were investigated through a combination of material mechanics and structural mechanics methods, in which the axial deformation of the rods was considered. The numerical results show that axial deformation has a significant influence on the elastic properties of irregular honeycomb structures. The elastic properties of the structure can be considered by the enclosed area of the unit structure, the shape of the unit structure, and the elastic properties of the original materials. The elastic properties considering the axial deformation of rods studied in this study can provide a reference for other scholars.

A plea for standardization of confocal microscopy and optical coherence tomography parameters to evaluate physiological and para-physiological skin conditions in cosmetic science.

Non-invasive reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) have been extended to the dermo-cosmetic field, for skin pathophysiology understanding and therapeutics monitoring. However, standardized methodology and parameters to interpret structures and changes in these settings are still lacking. Present study aimed to propose a validated standard methodology and a list of defined parameters for objective non-pathological skin assessments in the cosmetically sensitive cheekbone area of the face. OCT and RCM quantitative, semi-quantitative and qualitative features were considered for assessments. Validation process included 50 sets of images divided into two age groups. Inter-rater reliability was explored to assess the influence of the proposed methodology. Quantitative OCT parameters of "epidermal thickness," "density and attenuation coefficients" and "vascular density" were considered and calculated. Severity scales were developed for semi-quantitative OCT features of "disruption of collagen" and "vascular asset," while extent scales were produced for semi-quantitative RCM "irregular honeycomb," "mottled pigmentation" and "polycyclic papillary contours." Qualitative assessment was obtained for RCM type of collagen, and comparison between age groups was performed for all features considered. Severity visual scales assistance proved excellent inter-rater agreement across all semi-quantitative and qualitative domains. The assistance of shareable software systems allows for objective OCT quantitative parameters measurement. The use of standard reference scales, within a defined assessment methodology, offers high inter-rater reliability and thus reproducibility for semi-quantitative and qualitative OCT and RCM parameters. Taken together, our results may represent a starting point for a standardized application of RCM and OCT in dermo-cosmetic research and practice.

Skin photoaging in young men: A clinical study by skin imaging techniques.

Differences in skin physiology and lifestyle among people can influence the skin damage caused by solar radiation. Photoprotection habits play an important role to prevent skin photoaging. Thus, the objective of the present study was to evaluate the skin changes resulting from solar exposure in young men by skin imaging techniques. Twenty-three male, aged 18-28years, with and without photoprotection habits participated in the study. Instrumental measurements in terms of dermis thickness and echogenicity (20mHz ultrasound - DermaScanC® ), morphological and structural skin characterization (Reflectance Confocal Microscopy - VivaScope® 1500) and high-resolution imaging (Visioface® ) were performed in the malar region of the face. Pigmentation disorders, telangiectasia, wrinkles and lower dermis echogenicity were observed in the skin of subjects without photoprotection habits. Reflectance Confocal Microscopy images showed an irregular honeycomb pattern (35%), polycyclic papillae (40%) and coarse collagen fibres (35%), which are related to photoaging. Sun exposure without photoprotection results in a loss of dermal echogenicity and changes in the epidermis structure and collagen fibres regardless of chronological age. Thus, the study adds data for a discussion about correct photoprotection habits among young people and can help to increase the use of sunscreens for male public.

Surface-effect on detection ability of fluorescent Eu(btc) metal-organic frameworks to metal ions

Eu(btc) metal organic frameworks (MOFs) were prepared by co-precipitation method via 1,2,4-benzenetricarboxylic acids (H3btc) connecting with Eu3+ ions, and the morphology was controlled from compact spherical to irregular honeycomb by adjusting the pH of reaction solutions. The luminescence properties of Eu(btc) MOFs are found to be related to the surface morphology of products, and the compact spherical one performs stronger emission intensity. The sensing ability of Eu(btc) MOFs to 11 kinds of metal ions was investigated and a prominent quenching effect occurrs in Fe3+, Cr3+ or Ni2+ solutions. Based on UV–vis absorption analysis, an “ion-fence” model presents the competition to absorb exciting light between Eu(btc) MOFs and adsorbed metal ions. Based on Stern-Volmer equation, the Eu(btc) detection is found with higher Ksv value and a lower detection limit. Meanwhile, a higher sensing efficiency is confirmed in the Eu(btc) MOFs with loose honeycomb due to aggravating porous surface offering much more sites for metal ions.

Structural skin changes in elderly people investigated by reflectance confocal microscopy.

Reflectance confocal microscopy (RCM) is particularly suitable for the study of skin ageing because it provides nearly histological information in vivo and non-invasively. However, there are no studies that evaluated RCM skin features of a large population older than 70years. The aim of our investigation was to study age-related skin changes in an elderly population by RCM and to evaluate their topographical and gender differences. We obtained RCM images of photoprotected (volar arm) and chronic (face) and intermittently photoexposed (dorsal forearm) body sites of 209 volunteers (105 women and 104 men, mean age: 77.5, range 74-81years). 15 previously reported and new RCM parameters related to skin ageing were assessed. Photoexposed sites had thicker suprapapillary epidermis, more linear, distant and thin furrows, higher presence of mottled pigmentation, polycyclic papillae and coarse and huddled collagen and lower presence of dermal papillae than the photoprotected site. Irregular honeycomb pattern was not higher in photoexposed sites, indicating that it is probably more dependent on intrinsic ageing. Two ageing scores defined for facial skin ageing (epidermal disarray score and epidermal hyperplasia score) were found useful for the identification of photoageing. Gender differences only concerned some RCM parameters (i.e. thickness of different layers of the epidermis, furrows and collagen score) and some body sites, in line with the fact that women and men of our cohort had no major differences in clinically visible skin ageing. Our study confirmed that RCM is a powerful non-invasive technique to microscopically quantify ageing signs and our observations contribute to highlight the differences between intrinsic and extrinsic ageing.