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This study presents a systematic mechanical characterization of traditional materials employed in egg tempera painting techniques, focusing on gesso grounds and pigmented egg tempera layers. Gesso samples were prepared using rabbit skin glue, calcium carbonate, and titanium white pigment, while tempera paints were formulated with egg yolk binder and four representative mineral pigments: titanium white (TW), zinc white (ZW), yellow ochre (YO), and ultramarine blue (UB). Mechanical performance was assessed through micro-tensile and peeling tests. For gesso, the results demonstrate a strong dependence on Pigment Volume Concentration (PVC), with higher PVC values leading to reductions in both elastic modulus and ultimate tensile strength. For tempera paints, marked variability in elastic modulus was observed, with yellow ochre exhibiting the highest stiffness, whereas Titanium-rich formulations showed the greatest strain capacity at failure. In addition, adhesive fracture energy was quantified, providing the first dataset on the peeling resistance of these traditional materials. The results offer new insights into the fracture and adhesion behavior of tempera systems and establish a robust experimental framework that can support the development of conservation strategies for historical paintings.

Mechanical properties—modulus of elasticity and strain at break, water vapour sorption, and hygroscopic expansion of selected egg tempera and distemper paints were determined as a function of relative humidity (RH) filling in this way a critical gap in the knowledge required for the analysis of fracturing processes in paintings. The experimental work was made possible by the preparation of several tempera paints, mimicking the historical materials, in the form of large specimens. Lead white, azurite, and yellow ochre were selected as pigments, and egg yolk and rabbit skin glue as binding media. The water vapour sorption and the moisture-related swelling of the paints were dominated by the proteinaceous components of the binders. The linear hygroscopic expansion coefficient of the dried egg yolk binder was approximately 1 × 10−4 per 1% RH, several times less than the coefficient of the collagen glue (4 × 10−4 per 1% RH). The moduli of elasticity of egg tempera paints at the RH mid-range were comparable to the moduli of aged oil paints, whilst the modulus of elasticity of the distemper paint was close to values measured for animal glue-based grounds. The paints experienced the transition from brittle to ductile states on increasing RH. The egg tempera paints were found to be more brittle than the distemper paint, gessoes, and, generally, aged oil paints. The observations modify a frequently used laminar model of panel paintings in which the mismatch in the response of glue-based ground layer and wood substrate to variations in RH has been identified as the worst-case condition for the fracturing of the entire pictorial layer. This study demonstrated that tempera could be more brittle than the ground layer and in consequence more vulnerable to cracking.

Urban green spaces have many vital ecosystem services such as air cleaning, noise reduction, and carbon sequestration. Amid these great benefits from urban green spaces, the cooling effects via shading and evapotranspiration can mitigate the urban heat island effect. The impact of urban green spaces (UGSs) on the urban thermal environment in Beijing was quantified as a case study of metacities using four metrics: Land surface temperature (LST), cooling intensity, cooling extent, and cooling lapse. Three hundred and sixteen urban green spaces were extracted within the 4th ring road of Beijing from SPOT 6 satellite imagery and retrieved LST from Landsat 8 remote sensing data. The results showed that the cooling intensity of green spaces was generally more prominent in the areas with denser human activities and higher LST in this metacity. Vegetation density is always the dominant driver for the cooling effect indicated by all of the metrics. Furthermore, the results showed that those dispersive green spaces smaller than 9 ha, which are closely linked to the health and well-being of citizens, can possess about 6 °C of cooling effect variability, suggesting a great potential of managing the layout of small UGSs. In addition, the water nearby could be introduced to couple with the green and blue space for the promotion of cooling and enhancement of thermal comfort for tourists and residents. As the severe urban heating threatens human health and well-being in metacities, our findings may provide solutions for the mitigation of both the urban heat island and global climate warming of the UGS area customized cooling service.

Non-destructive diagnostic approaches play a crucial role in cultural heritage studies by enabling the assessment of artworks’ conservation conditions without causing damage. This work presents the case study of the tempera painting Cristo in Trono, by Domenico Morelli and Paolo Vetri, located in Amalfi (SA, Italy). A multi-analytical approach combining portable and non-invasive techniques was employed. Hygrometric tomography revealed anomalous surface moisture values (up to 23 units) along the edges and wooden joints, identifying areas requiring particular attention during conservation. Infrared reflectography (IR-R) detected preparatory drawings, compositional changes, and evidence of previous restoration interventions. X-ray fluorescence spectroscopy (XRF) identified the elemental composition of the pigments, indicating the use of cinnabar (or vermilion), ultramarine (or lapis lazuli), ochres, lead white (Biacca), and brass (Orone) for the golden background. Multivariate statistical analysis of the XRF data (PCA and HCA) revealed compositional heterogeneity and chemically distinct areas within apparently similar chromatic regions. Micro-invasive analyses complemented these results by providing information on the stratigraphy and material composition. Fourier-transform infrared (FT-IR) spectroscopy identified polyvinyl acetate (PVA), attributed to previous restoration treatments and associated with the yellowing of lead white, together with protein-based binders. Microscopic observations revealed the woven structure of the support, pigment-layer cracking, and degradation features, while the interaction of the brass with atmospheric agents and marine chlorides was found to be responsible for the alteration of the original golden background to a greenish-gold hue. The lower part of the canvas exhibited the most severe deterioration, resulting from higher moisture levels, unsuitable past restoration treatments, and prolonged exposure to humidity, atmospheric pollutants, and marine aerosols, highlighting the importance of integrated diagnostic investigations for planning effective conservation and restoration strategies.

The transformation of steroids by microorganisms is widely used in medical biotechnology. A huge group of filamentous fungi is one of the most promising taxa for screening new biocatalytic reactions in order to obtain pharmaceutically significant steroids. In this work, we screened 10 filamentous fungi-destructors of egg tempera for the ability to biotransform androst-4-en-3,17-dione (AD) during cultivation in a liquid nutrient medium or in a buffer solution. These taxonomically unrelated strains, belonging to the classes Eurotiomycetes, Dothideomycetes and Sordariomycetes, are dominant representatives of the microbiome from halls where works of tempera painting are stored in the State Tretyakov Gallery (STG, Moscow, Russia). Since the binder of tempera paints, egg yolk, contains about 2% cholesterol, these degrading fungi appear to be a promising group for screening for steroid converting activity. It turned out that all the studied fungi-destructors are able to transform AD. Some strains showed transformation efficiency close to the industrial strain Curvularia lunata RNCIM F-981. In total, 33 steroids formed during the transformation of AD were characterized, for 19 of them the structure was established by gas chromatography/mass spectrometry analysis. In this work, we have shown for the first time that fungi-destructors of tempera paintings can efficiently transform steroids.

The molecular basis of the thermal sensitivity of temperature-sensitive channels appears to arise from a specific protein domain rather than integration of global thermal effects. Using systematic chimeric analysis, we show that the N-terminal region that connects ankyrin repeats to the first transmembrane segment is crucial for temperature sensing in heat-activated vanilloid receptor channels. Changing this region both transformed temperature-insensitive isoforms into temperature-sensitive channels and significantly perturbed temperature sensing in temperature-sensitive wild-type channels. Swapping other domains such as the transmembrane core, the C terminus, and the rest of the N terminus had little effect on the steepness of temperature dependence. Our results support that thermal transient receptor potential channels contain modular thermal sensors that confer the unprecedentedly strong temperature dependence to these channels.

Lowest-energy structures, the distribution of isomers, and their molecular properties depend significantly on geometry and temperature. Total energy computations using DFT methodology are typically carried out at a temperature of zero K; thereby, entropic contributions to the total energy are neglected, even though functional materials work at finite temperatures. In the present study, the probability of the occurrence of one particular Be4B8 isomer at temperature T is estimated by employing Gibbs free energy computed within the framework of quantum statistical mechanics and nanothermodynamics. To identify a list of all possible low-energy chiral and achiral structures, an exhaustive and efficient exploration of the potential/free energy surfaces is carried out using a multi-level multistep global genetic algorithm search coupled with DFT. In addition, we discuss the energetic ordering of structures computed at the DFT level against single-point energy calculations at the CCSD(T) level of theory. The total VCD/IR spectra as a function of temperature are computed using each isomer’s probability of occurrence in a Boltzmann-weighted superposition of each isomer’s spectrum. Additionally, we present chemical bonding analysis using the adaptive natural density partitioning method in the chiral putative global minimum. The transition state structures and the enantiomer–enantiomer and enantiomer–achiral activation energies as a function of temperature evidence that a change from an endergonic to an exergonic type of reaction occurs at a temperature of 739 K.

Accurate and frequent monitoring of evapotranspiration (ET) at sub-field scales can provide valuable information for agricultural water management, quantifying crop water use and stress toward the goal of increasing crop water use efficiency and production. Using land-surface temperature (LST) data retrieved from Landsat thermal infrared (TIR) imagery, along with surface reflectance data describing albedo and vegetation cover fraction, surface energy balance models can generate ET maps down to a 30 m spatial resolution. However, the temporal sampling by such maps can be limited by the relatively infrequent revisit period of Landsat data (8 days for combined Landsats 7 and 8), especially in cloudy areas experiencing rapid changes in moisture status. The Sentinel-2 (S2) satellites, as a good complement to the Landsat system, provide surface reflectance data at 10–20 m spatial resolution and 5 day revisit period but do not have a thermal sensor. On the other hand, the Visible Infrared Imaging Radiometer Suite (VIIRS) provides TIR data on a near-daily basis with 375 m resolution, which can be refined through thermal sharpening using S2 reflectances. This study assesses the utility of augmenting the Harmonized Landsat and Sentinel-2 (HLS) dataset with S2-sharpened VIIRS as a thermal proxy source on S2 overpass days, enabling 30 m ET mapping at a potential combined frequency of 2–3 days (including Landsat). The value added by including VIIRS-S2 is assessed both retrospectively and operationally in comparison with flux tower observations collected from several U.S. agricultural sites covering a range of crop types. In particular, we evaluate the performance of VIIRS-S2 ET estimates as a function of VIIRS view angle and cloud masking approach. VIIRS-S2 ET retrievals (MAE of 0.49 mm d−1 against observations) generally show comparable accuracy to Landsat ET (0.45 mm d−1) on days of commensurate overpass, but with decreasing performance at large VIIRS view angles. Low-quality VIIRS-S2 ET retrievals linked to imperfect VIIRS/S2 cloud masking are also discussed, and caution is required when applying such data for generating ET timeseries. Fused daily ET time series benefited during the peak growing season from the improved multi-source temporal sampling afforded by VIIRS-S2, particularly in cloudy regions and over surfaces with rapidly changing vegetation conditions, and value added for real-time monitoring applications is discussed. This work demonstrates the utility and feasibility of augmenting the HLS dataset with sharpened VIIRS TIR imagery on S2 overpass dates for generating high spatiotemporal resolution ET products.

Background: The coronavirus disease in 2019 (COVID-19) heavily hit Italy, one of Europe’s most polluted countries. The extent to which PM pollution contributed to COVID-19 diffusion is needing further clarification. We aimed to investigate the particular matter (PM) pollution and its correlation with COVID-19 incidence across four Italian cities: Milan, Rome, Naples, and Salerno, during the pre-lockdown and lockdown periods. Methods: We performed a comparative analysis followed by correlation and regression analyses of the daily average PM10, PM2.5 concentrations, and COVID-19 incidence across four cities from 1 January 2020 to 8 April 2020, adjusting for several factors, taking a two-week time lag into account. Results: Milan had significantly higher average daily PM10 and PM2.5 levels than Rome, Naples, and Salerno. Rome, Naples, and Salerno maintained safe PM10 levels. The daily PM2.5 levels exceeded the legislative standards in all cities during the entire period. PM2.5 pollution was related to COVID-19 incidence. The PM2.5 levels and sampling rate were strong predictors of COVID-19 incidence during the pre-lockdown period. The PM2.5 levels, population’s age, and density strongly predicted COVID-19 incidence during lockdown. Conclusions: Italy serves as a noteworthy paradigm illustrating that PM2.5 pollution impacts COVID-19 spread. Even in lockdown, PM2.5 levels negatively impacted COVID-19 incidence.

The cleaning and consolidation of egg white tempera were evaluated to help conserve a polychrome sculpture, the funeral coat of arms of Pehr Stålhammar, dated 1701. This coat of arms was a wooden structure of carved pine and lime wood, grounded with a chalk and rabbit skin glue ground layer, and polychromed with egg white tempera in combination with smalt blue, lamp black, and red pigments.Due to the difficulties of preserving the physical properties of egg white tempera, it was necessary to evaluate the consolidation effects in terms of color, gloss, and cohesion. Four consolidants were chosen: JunFunori, sturgeon glue, Aquazol 200, and Lascaux’s Medium for Consolidation. Among these, Aquazol 200 and JunFunori performed more efficiently.Another type of difficulty occurred during the conservation cleaning treatment process, especially with the blue paint, which is more fragile and has hydrophobic qualities. To conceive a safe cleaning method, various cleaning techniques and materials were tested with a microscope, scanning electron microscopy, and an artificial aging chamber. The investigation showed that the dry cleaning method and use of hydrogels could work together and target different tasks.