Differences of skin carotenoids and adherence to the Mediterranean Diet pattern in adults from Southern Italy and Dominican Republic.

BACKGROUND: The measurement of the skin carotenoids using the Veggie Meter® has emerged as a rapid objective method for assessing fruit and vegetable intake, highly recommended by the Mediterranean Diet (MD), which represents one of the healthiest dietary patterns, worldwide. This study aimed to examine differences in skin carotenoid content and degree of adherence to the MD pattern between two adult populations from Southern Italy and the Dominican Republic. METHODS: This cross-sectional study enrolled a total of 995 adults, 601 subjects from Italy and 394 from the Dominican Republic. All participants underwent anthropometric measurements and skin carotenoid assessment by Veggie Meter®. Adherence to the MD and lifestyle were evaluated using the Mediterranean Diet Adherence Screener (MEDAS) and the Mediterranean Lifestyle Index (MEDLIFE) questionnaires. Correlations between the skin carotenoid and MEDAS score were estimated using Pearson's correlation coefficient. Multiple linear regression models were created to determine variables that affect skin carotenoid score for both populations. RESULTS: Mean total skin carotenoids were higher in the Italian compared to the Dominican Republic population (342.4 ± 92.4 vs 282.9 ± 90.3; p < 0.005) regardless of sex (women: 318.5 ± 88.9 vs 277.3 ± 91.9, p < 0.005 and men: 371.7 ± 88.3 vs 289.5 ± 88.1, p < 0.005), and remaining statistically significant after age-adjustment of the Dominican Republic sample. Using the MEDAS questionnaire, we found a higher MD adherence score in the Italian than in the Dominican Republic population also after age-adjusting data (7.8 ± 2.1 vs 6.2 ± 3.7; p < 0.005) and even when categorized by sex (Italian vs age-adjusted Dominican Republic women: 7.9 ± 2.1 vs 6.3 ± 2.6; Italian vs age-adjusted Dominican Republic men: 7.7 ± 2.2 vs 6.0 ± 4.7; p < 0.005). Using the MEDLIFE test, total Italians presented a lower score with respect to the age-adjusted Dominican Republic population (3.2 ± 1.2 vs 3.4 ± 1.4; p < 0.05). In multiple regression analysis, skin carotenoids were associated with sex and negatively associated with BMI in the Italian population (sex: ß: 54.95; 95% CI: 40.11, 69.78; p < 0.0001; BMI: ß: - 1.60; 95% CI: - 2.98,0.86; p = 0.03), while they resulted associated with age and sex in the Dominican Republic population (age: ß: 2.76; 95% CI: 1.92, 3.56; p < 0.001; sex: ß: 23.29; 95% CI: 5.93, 40.64; p = 0.009). Interestingly, skin carotenoids were positively correlated with MEDAS score in both populations (Italy: r = 0.03, p < 0.0001, Dominican Republic: r = 0.16, p = 0.002). CONCLUSIONS: This study provides the assessment of the adherence to the MD and skin carotenoid content in adults living in Southern Italy and the Dominican Republic, showing a higher MD adherence score and a skin carotenoid content in inhabitants from the Mediterranean region. Our findings highlight the need to globally encourage fruit and vegetable intake, particularly in non-Mediterranean area.

Tunable optical and semiconducting properties of eco-friendly-prepared reduced graphene oxide.

Wide bandgap oxidized graphenes have garnered particular interest among the materials explored for these applications because of their exceptional semiconducting and optical properties. This study aims to investigate the tunability of the related properties in reduced graphene oxide (rGO) for potential use in energy conversion, storage, and optoelectronic devices. To accomplish this, we scrutinized crucial parameters of the synthesis process such as reduction time and temperature. Our findings demonstrate that controlling these parameters makes it possible to customize the optical bandgap of reduced graphene oxide within a range of roughly 2.2 eV-1.6 eV. Additionally, we observed that reduced graphene oxide has strong and superior absorption in the visible region, which is attributable to the existence of OFGs and defects. Notably, our results indicate that the absorption coefficients of reduced graphene oxide are up to almost three times higher (7426 ml mg-1 m-1) than those observed in dispersions of exfoliated graphene and graphene oxide (GO). To complement our findings, we employed several spectroscopic and morphological characterizations, including scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and electrical measurements. The implications of our results are significant for the development and design of future semiconductors for energy conversion and optoelectronic applications.

Temperature-Dependent Optical Properties of Oxidized Graphenes.

In this study, we investigate how changing important synthesis-related parameters can affect and control the optical characteristics of graphene oxide (GO) and reduced graphene oxide (rGO). These parameters include drying time and reduction time at two different temperatures. We obtain an understanding of their impact on optical transitions, optical bandgap, absorption coefficient, and absorbance spectrum width by analyzing these factors. Accordingly, GO has an optical bandgap of about 4 eV, which is decreased by the reduction process to 1.9 eV. Both GO and rGO display greater absorption in the visible spectrum, which improves photon capture and boosts efficiency in energy conversion applications. Additionally, our results show that GO and rGO have higher absorption coefficients than those previously reported for dispersions of exfoliated graphene. Defects in GO and rGO, as well as the presence of functional oxygen groups, are the main contributors to this increased absorption. Several measurements are carried out, including spectroscopic and morphological studies, to further support our findings.

Stable Supercapacitors Based on Activated Carbon Prepared from Italian Orange Juice.

The development of efficient energy storage systems is critical in the transition towards sustainable energy solutions. In this context, the present work investigates the viability of using orange juice, as a promising and sustainable precursor, for the synthesis of activated carbon electrodes for supercapacitor technologies. Through the carbonization-activation process and controlling the preparation parameters (KOH ratio and activation time), we have tailored the specific surface area (SSA) and pore size distribution (PSD) of the resulting carbon materials-crucial parameters that support supercapacitive performance. Several spectroscopic, morphological, and electrochemical techniques are used to characterize the obtained carbon materials. In particular, our optimization efforts revealed that a 5:1 KOH ratio with an activation time up to 120 min produced the highest SSA of about 2203 m2/g. Employing these optimal conditions, we fabricated symmetric coin cell supercapacitors using Na2SO4 as the electrolyte, which exhibited interesting specific capacitance (~56 F/g). Durability testing over 5000 cycles sustained the durability of the as-made activated carbon electrodes, suggesting an excellent retention of specific capacitance. This study not only advances the field of energy storage by introducing a renewable material for electrode fabrication but also contributes to the broader goal of waste reduction through the repurposing of food byproducts.

Adsorption of Mercury on Oxidized Graphenes.

Graphene oxide (GO) and its reduced form, reduced graphene oxide (rGO), are among the most predominant graphene derivatives because their unique properties make them efficient adsorbent nanomaterials for water treatment. Although extra-functionalized GO and rGO are customarily employed for the removal of pollutants from aqueous solutions, the adsorption of heavy metals on non-extra-functionalized oxidized graphenes has not been thoroughly studied. Herein, the adsorption of mercury(II) (Hg(II)) on eco-friendly-prepared oxidized graphenes is reported. The work covers the preparation of GO and rGO as well as their characterization. In a further stage, the description of the adsorption mechanism is developed in terms of the kinetics, the associated isotherms, and the thermodynamics of the process. The interaction between Hg(II) and different positions of the oxidized graphene surface is explored by DFT calculations. The study outcomes particularly demonstrate that pristine rGO has better adsorbent properties compared to pristine GO and even other extra-functionalized ones.

Removal of mercury(II) from aqueous solution by partially reduced graphene oxide.

Mercury (Hg(II)) has been classified as a pollutant and its removal from aqueous sources is considered a priority for public health as well as ecosystem protection policies. Oxidized graphenes have attracted vast interest in water purification and wastewater treatment. In this report, a partially reduced graphene oxide is proposed as a pristine adsorbent material for Hg(II) removal. The proposed material exhibits a high saturation Hg(II) uptake capacity of 110.21 mg g-1, and can effectively reduce the Hg(II) concentration from 150 mg L-1 to concentrations smaller than 40 mg L-1, with an efficiency of about 75% within 20 min. The adsorption of Hg(II) on reduced graphene oxide shows a mixed physisorption-chemisorption process. Density functional theory calculations confirm that Hg atom adsorbs preferentially on clean zones rather than locations containing oxygen functional groups. The present work, therefore, presents new findings for Hg(II) adsorbent materials based on partially reduced graphene oxide, providing a new perspective for removing Hg(II).

Cationic Pollutant Removal from Aqueous Solution Using Reduced Graphene Oxide.

Reduced graphene oxide (rGO) is one of the most well-known graphene derivatives, which, due to its outstanding physical and chemical properties as well as its oxygen content, has been used for wastewater treatment technologies. Particularly, extra functionalized rGO is widely preferred for treating wastewater containing dyes or heavy metals. Nevertheless, the use of non-extra functionalized (pristine) rGO for the removal of cationic pollutants is not explored in detail or is ambiguous. Herein, pristine rGO-prepared by an eco-friendly protocol-is used for the removal of cationic pollutants from water, i.e., methylene blue (MB) and mercury-(II) (Hg-(II)). This work includes the eco-friendly synthesis process and related spectroscopical and morphological characterization. Most importantly, the investigated rGO shows an adsorption capacity of 121.95 mg g-1 for MB and 109.49 mg g-1 for Hg (II) at 298 K. A record adsorption time of 30 min was found for MB and 20 min for Hg (II) with an efficiency of about 89% and 73%, respectively. The capture of tested cationic pollutants on rGO exhibits a mixed physisorption-chemisorption process. The present work, therefore, presents new findings for cationic pollutant adsorbent materials based on oxidized graphenes, providing a new perspective for removing MB molecules and Hg(II) ions.

Drying-Time Study in Graphene Oxide.

Graphene oxide (GO) exhibits different properties from those found in free-standing graphene, which mainly depend on the type of defects induced by the preparation method and post-processing. Although defects in graphene oxide are widely studied, we report the effect of drying time in GO and how this modifies the presence or absence of edge-, basal-, and sp3-type defects. The effect of drying time is evaluated by Raman spectroscopy, UV-visible spectroscopy, and transmission electron microscopy (TEM). The traditional D, G, and 2D peaks are observed together with other less intense peaks called the D', D*, D**, D+G, and G+D. Remarkably, the D* peak is activated/deactivated as a direct consequence of drying time. Furthermore, the broad region of the 2D peak is discussed as a function of its deconvoluted 2D1A, 2D2A, and D+G bands. The main peak in UV-visible absorption spectra undergoes a redshift as drying time increases. Finally, TEM measurements demonstrate the stacking of exfoliated GO sheets as the intercalated (water) molecules are removed.

Porous Carbon Materials Obtained by the Hydrothermal Carbonization of Orange Juice.

Porous carbon materials are currently subjected to strong research efforts mainly due to their excellent performances in energy storage devices. A sustainable process to obtain them is hydrothermal carbonization (HTC), in which the decomposition of biomass precursors generates solid products called hydrochars, together with liquid and gaseous products. Hydrochars have a high C content and are rich with oxygen-containing functional groups, which is important for subsequent activation. Orange pomace and orange peels are considered wastes and then have been investigated as possible feedstocks for hydrochars production. On the contrary, orange juice was treated by HTC only to obtain carbon quantum dots. In the present study, pure orange juice was hydrothermally carbonized and the resulting hydrochar was filtered and washed, and graphitized/activated by KOH in nitrogen atmosphere at 800 °C. The resulting material was studied by transmission and scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and nitrogen sorption isotherms. We found porous microspheres with some degree of graphitization and high nitrogen content, a specific surface of 1725 m2/g, and a pore size distribution that make them good candidates for supercapacitor electrodes.

The Adsorption of Methylene Blue on Eco-Friendly Reduced Graphene Oxide.

Recently, green-prepared oxidized graphenes have attracted huge interest in water purification and wastewater treatment. Herein, reduced graphene oxide (rGO) was prepared by a scalable and eco-friendly method, and its potential use for the removal of methylene blue (MB) from water systems, was explored. The present work includes the green protocol to produce rGO and respective spectroscopical and morphological characterizations, as well as several kinetics, isotherms, and thermodynamic analyses to successfully demonstrate the adsorption of MB. The pseudo-second-order model was appropriated to describe the adsorption kinetics of MB onto rGO, suggesting an equilibrium time of 30 min. Otherwise, the Langmuir model was more suitable to describe the adsorption isotherms, indicating a maximum adsorption capacity of 121.95 mg g-1 at 298 K. In addition, kinetics and thermodynamic analyses demonstrated that the adsorption of MB onto rGO can be treated as a mixed physisorption-chemisorption process described by H-bonding, electrostatic, and π - π interactions. These results show the potential of green-prepared rGO to remove cationic dyes from wastewater systems.

Toward Large-Scale Production of Oxidized Graphene.

The oxidative exfoliation of graphite is a promising approach to the large-scale production of graphene. Conventional oxidation of graphite essentially facilitates the exfoliation process; however, the oxidation procedure releases toxic gases and requires extensive, time-consuming steps of washing and reduction to convert exfoliated graphene oxide (GO) into reduced graphene oxide (rGO). Although toxic gases can be controlled by modifying chemical reactions, filtration, dialysis, and extensive sonication are unfavorable for large-scale production. Here, we report a complete, scalable, and green synthesis of GO, without NaNO3, followed by reduction with citric acid (CA). This approach eliminates the generation of toxic gases, simplifies the washing steps, and reduces the time required to prepare rGO. To validate the proposed method, we present spectroscopical and morphological studies, using energy-dispersive X-ray spectroscopy (EDS), UV-visible spectroscopy, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Thermal gravimetric analysis (TGA) is used to analyze the thermal properties of GO and rGO. This eco-friendly method proposes a complete guideline protocol toward large-scale production of oxidized graphene, with potential applications in supercapacitors, fuel cells, composites, batteries, and biosensors.

The Advent of Indium Selenide: Synthesis, Electronic Properties, Ambient Stability and Applications.

Among the various two-dimensional semiconductors, indium selenide has recently triggered the interest of scientific community, due to its band gap matching the visible region of the electromagnetic spectrum, with subsequent potential applications in optoelectronics and especially in photodetection. In this feature article, we discuss the main issues in the synthesis, the ambient stability and the application capabilities of this novel class of two-dimensional semiconductors, by evidencing open challenges and pitfalls. In particular, we evidence how the growth of single crystals with reduced amount of Se vacancies is crucial in the road map for the exploitation of indium selenide in technology through ambient-stable nanodevices with outstanding values of both mobility of charge carriers and ON/OFF ratio. The surface chemical reactivity of the InSe surface, as well as applications in the fields of broadband photodetection, flexible electronics and solar energy conversion are also discussed.