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Light-absorbing aerosols heat the atmosphere; an accurate quantification of their absorption coefficient is mandatory. However, standard reference instruments (CAPS, MAAP, PAX, PTAAM) are not always available at each measuring site around the world. By integrating all previous published studies concerning the Aethalometers, the AE33 filter loading parameter, provided by the dual-spot algorithm, were used to determine the multiple scattering enhancement factor from the Aethalometer itself (hereinafter C AE ) on an yearly and a monthly basis. The method was developed in Milan, where Aethalometer measurements were compared with MAAP data; the comparison showed a good agreement in terms of equivalent black carbon (R 2  = 0.93; slope = 1.02 and a negligible intercept = 0.12 μg m -3 ) leading to a yearly experimental multiple scattering enhancement factor of 2.51 ± 0.04 (hereinafter C MAAP ). On a yearly time base the C AE values obtained using the new approach was 2.52 ± 0.01, corresponding to the experimental one (C MAAP ). Considering the seasonal behavior, higher experimental C MAAP and computed C AE values were found in summer (2.83 ± 0.12) whereas, the lower ones in winter/early-spring (2.37 ± 0.03), in agreement with the single scattering albedo behavior in the Po Valley. Overall, the agreement between the experimental C MAAP and C AE showed a root mean squared error (RMSE) of just 0.038 on the C MAAP prediction, characterized by a slope close to 1 (1.001 ± 0.178), a negligible intercept (-0.002 ± 0.455) and a high degree of correlation (R 2  = 0.955). From an environmental point of view, the application of a dynamic (space/time) determination of C AE increases the accuracy of the aerosol heating rate (compared to applying a fixed C value) up to 16 % solely in Milan, and to 114 % when applied in the Arctic at 80°N., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Luca Ferrero reports financial support was provided by University of Milan-Bicocca., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Particulate matter (PM) pollution is one of the major threats to cultural heritage outdoors. It has been recently implied that organic aerosols will prevail over inorganic carbon particulates in the future, changing the main mechanisms of damage caused by poor air quality to calcareous heritage in particular. We studied fresh particulate deposits on marble and limestone surfaces exposed to urban air in sheltered and unsheltered configurations. Due to different air pollution sources in different seasons, the amount and composition of surface deposits varied throughout the year. The main and most constant contributor to PM 2.5 (particles smaller than 2.5 μm) were primary traffic emissions (30 %), followed by secondary formation of acidic inorganic aerosols, such as sulphate in summer and nitrate in winter (33 % altogether), and seasonal biomass-burning emissions (14 %). Although biomass burning is the major source of primary organic aerosols including the light-absorbing fraction that prevailed over black carbon (BC) in colder months (up to 60 % carbonaceous aerosol mass), we show that surface darkening causing the soiling effect is still governed by the minor BC fraction of atmospheric aerosols, which remained below 20 % of the carbonaceous aerosol mass throughout the year. This, however, can change in remote environments affected by biomass-burning emissions, such as winter resorts, or by rigorous BC mitigation measures in the future. In the short run, sheltered positions were less affected by different removal processes, but we show that surface deposits are not simply additive when considering longer periods of time. This must be taken into account when extrapolating surface accumulation to longer time scales., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Asta Gregorič, Matic Ivančič and Martin Rigler are employed by the company Aerosol d.o.o., which develops and manufactures aerosol instrumentation, including the CASS instrument used in the campaigns., (Copyright © 2022 Elsevier B.V. All rights reserved.)

In recent years, carbonaceous aerosols (CA) have been recognized as a significant contributor to the concentration of particles smaller than 2.5 μm (i.e., PM 2.5 ), with a negative impact on public health and Earth's radiative balance. In this study, we present a method for CA apportionment based on high-time-resolution measurements of total carbon (TC), black carbon (BC), and spectral dependence of absorption coefficient using a recently developed Carbonaceous Aerosol Speciation System (CASS). Two-year-long CA measurements at two different locations within California's Los Angeles Basin are presented. CA was apportioned based on its optical absorption properties, organic or elemental carbon composition, and primary or secondary origin. We found that the secondary organic aerosols (SOA), on average, represent >50 % of CA in the study area, presumably resulting from the oxidation of anthropogenic and biogenic volatile organic components. Remarkable peaks of SOA in summer afternoons were observed, with a fractional contribution of up to 90 %. On the other hand, the peak of primary emitted CA, consisting of BC and primary organic aerosol (POA), contributed >80 % to the CA during morning rush hours on winter working days. The light absorption of BC dominated over the brown carbon (BrC), which contributed to 20 % and 10 % of optical absorption at the lower wavelength of 370 nm during winter nights and summer afternoons, respectively. The highest contribution of BrC, up to 50 %, was observed during the wildfire periods. Although the uncertainty levels can be high for some CA components (such as split between primary emitted and secondary formed BrC during winter nights), further research focused on the optical properties of CA at different locations may help to better constrain the parameters used in CA apportionment studies. We believe that the CASS system combined with the apportionment method presented in this study can offer simplified and cost-effective insights into the composition of carbonaceous aerosols., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: At the time of the research, Matic Ivančič, Asta Gregorič, Gašper Lavrič, Bálint Alföldy, Irena Ježek, and Martin Rigler were also employed by the manufacturer of the Aethalometer and Total carbon analyzer instruments. Other authors declare no conflict of interest. The views expressed in this document are solely those of the authors and do not necessarily reflect those of the South Coast AQMD., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Accurate and temporally consistent measurements of light absorbing aerosol (LAA) heating rate (HR) and of its source apportionment (fossil-fuel, FF; biomass-burning, BB) and speciation (black and brown Carbon; BC, BrC) are needed to evaluate LAA short-term climate forcing. For this purpose, wavelength- and time-dependent accurate LAA absorption coefficients are required. HR was experimentally determined and apportioned (sources/species) in the EMEP/ACTRIS/COLOSSAL-2018 winter campaign in Milan (urban-background site). Two Aethalometers (AE31/AE33) were installed together with a MAAP, CPC, OPC, a low volume sampler (PM 2.5 ) and radiation instruments. AE31/AE33 multiple-scattering correction factors (C) were determined using two reference systems for the absorption coefficient: 1) 5-wavelength PP_UniMI with low time resolution (12 h, applied to PM 2.5 samples); 2) timely-resolved MAAP data at a single wavelength. Using wavelength- and time-independent C values for the AE31 and AE33 obtained with the same reference device, the total HR showed a consistency (i.e. reproducibility) with average values comparable at 95% probability. However, if different reference devices/approaches are used, i.e. MAAP is chosen as reference instead of a PP_UniMI, the HR can be overestimated by 23-30% factor (by both AE31/AE33). This became more evident focusing on HR apportionment: AE33 data (corrected by a wavelength- and time-independent C) showed higher HR FF (+24 ± 1%) and higher HR BC (+10 ± 1%) than that of AE31. Conversely, HR BB and HR BrC were -28 ± 1% and -29 ± 1% lower for AE33 compared to AE31. These inconsistencies were overcome by introducing a wavelength-dependent C λ for both AE31 and AE33, or using multi-wavelength apportionment methods, highlighting the need for further studies on the influence of wavelength corrections for HR determination. Finally, the temporally-resolved determination of C resulted in a diurnal cycle of the HR not statistically different whatever the source- speciation- apportionment used., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background & Aims: Patients in the Intensive Care Unit (ICU) are at high risk of malnutrition. The only validated malnutrition assessment tool is the Subjective Global Assessment (SGA). The Global Leadership Initiative on Malnutrition (GLIM) is a new malnutrition assessment tool. The present study compares the nutrition-related parameters of the following tools: GLIM tool, SGA, Phase Angle (PA), Low Fat-Free Mass Index (FFMI), and Patient- and Nutrition-Derived Outcome Risk Assessment score (PANDORA), in an attempt to validate an objective tool., Methods: Eighty-four ICU patients were included. The tools mentioned above were assessed for their validity in diagnosing malnutrition. All patients were defined as suffering from acute disease and received medical nutrition therapy. To evaluate whether there is a correlation between the GLIM criteria, SGA, PA, and low FFMI, we compared the SGA, PA, and low FFMI to the GLIM criteria using Spearman correlation coefficients and a Chi-square test. Also, a Mann-Whitney U test was used to test the mean differences between the GLIM criteria and the PANDORA. The area under the curve (AUC) of the proposed parameters was evaluated for diagnosis of malnutrition to seek cutoff points that yield good sensitivity and specificity., Results: Mean age was 50 ± 20 years, BMI 25.3 ± 5.1 kg/m 2 , APACHE II 20.5 ± 7.7, PANDORA score 32 ± 8.5. GLIM malnutrition criteria were significantly correlated with the gold standard SGA assessment and with low FFMI, with PA (Phase Angle), and with the PANDORA score. The area under the curve, by using the ROC curve analysis for GLIM criteria stratified by the SGA results, was 0.85 (P < 0.001). Sensitivity was 85%, and specificity 79%. However, when comparing the low FFMI, PA, and PANDORA to the GLIM criteria, the ROC curve analysis results were considered poor rank., Conclusions: The SGA malnutrition assessment highly validated the GLIM criteria framework combined with the two-criteria diagnosis of malnutrition with a high level of precision. The GLIM malnutrition assessment seems to be acceptable in the ICU setting., Competing Interests: Conflict of interest The authors have no conflicts of interest to declare., (Copyright © 2020 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.)

Background & Aims: Enteral nutrition (EN) and parenteral nutrition (PN) enriched with omega-3 polyunsaturated fatty acids (PUFA) have beneficial effects in critical illness. This study aimed to assess the combined effect of EN and supplemental PN enriched with omega-3 PUFA on blood oxygenation in intensive care unit (ICU) patients., Methods: Single-center, prospective, randomized, controlled, double-blind, phase III trial conducted from 10/2013 to 11/2017. A total of 100 ICU patients (18-85 years, APACHE II score > 15) requiring mechanical ventilation were randomly assigned to received combined EN and PN either with omega-3 PUFA (omega-3 group) or without (control group) for up to 28 days. Primary endpoint: 'change of PaO 2 /FiO 2 from day (D) 1 to D4'. Secondary endpoints: lung function parameters, ICU complications, length of hospital stay, days free of ICU care/ventilation/sedation/catecholamine treatment, mortality, erythrocyte fatty acid composition, inflammatory parameters. Safety parameters: standard laboratory assessment, vital signs, physical examination, SOFA score, adverse events., Results: Combined EN and PN covered energy requirements to more than 80%. Blood oxygenation (ΔPaO 2 /FiO 2 from D1 to D4: -1.3 ± 83.7, n = 42, and 13.3 ± 86.1, n = 39, in omega-3 and control group, respectively, p = 0.7795) and other lung function parameters did not differ between groups but days free of catecholamine treatment were significantly higher in the omega-3 group (~4 days, p = 0.0481). On D6, significantly more patients in the omega-3 group tolerated EN alone (51.0% vs. 29.8%, p = 0.0342). Eicosapentaenoic acid (EPA) content in erythrocytes was significantly increased in the omega-3 group at last observation compared with the control group (ΔEPA: 0.928 ± 0.808% vs. -0.024 ± 0.190%, p < 0.0001). No further significant group differences were detected., Conclusions: Enteral and supplemental PN both enriched with omega-3 PUFA did not improve lung function but allowed earlier weaning from catecholamine treatment and PN. Supplemental PN succeeded to adequately cover energy requirements in critically ill patients., Trial Registration: www.clinicaltrials.gov, registration number: NCT01162928., Competing Interests: Conflict of interest PS received speaker fees. All the other authors do not declare any conflict of interest., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)