Search

The formation of corrosion products and the corrosion sensitivity of copper and lead were studied under experimental conditions in which formaldehyde (methanal), formic (methanoic) and acetic (ethanoic) acid concentration, relative humidity (RH) and duration of exposure were varied. Levels of formic acid above 0.4 parts per million based on volume (ppmv) affect the appearance of copper at 75% RH, and at levels above 4 ppmv the copper gains weight at both 54 and 75% RH. The main compound found on copper was cuprite, copper(I) oxide. Lead has a higher sensitivity to formic acid: at levels as low as 0.04 ppmv lead becomes darker, and at above 0.1 ppmv weight gains were measurable at both 54 and 75% RH. In the presence of different levels of mixed carbonyl vapours at 75% RH, copper reacted mainly with formic acid. On the other hand, the reaction of lead was more complex. Acetic acid tends to form a thick white layer (composed mainly of plumbonacrite and possibly lead acetate compounds) on the lead surface, while formic acid tends to form a rather thin and darker layer of lead formate hydroxide. In the presence of formic acid, the action of acetic acid on lead was inhibited. At levels of formaldehyde up to 3 ppmv, no significant contribution of formaldehyde to the corrosion process on lead and copper was observed. [ABSTRACT FROM AUTHOR]

Although yellow and orange petal colors are derived from carotenoids in many plant species, this has not yet been demonstrated for the order Caryophyllales, which includes carnations. Here, we identified a carnation cultivar with pale yellow flowers that accumulated carotenoids in petals. Additionally, some xanthophyll compounds were esterified, as is the case for yellow flowers in other plant species. Ultrastructural analysis showed that chromoplasts with numerous plastoglobules, in which flower-specific carotenoids accumulate, were present in the pale yellow petals. RNA-seq and RT-qPCR analyses indicated that the expression levels of genes for carotenoid biosynthesis and esterification in pale yellow and pink petals (that accumulate small amounts of carotenoids) were similar or lower than in green petals (that accumulate substantial amounts of carotenoids) and white petals (that accumulate extremely low levels of carotenoids). Pale yellow and pink petals had a considerably lower level of expression of genes for carotenoid degradation than white petals, suggesting that reduced degradation activity caused accumulation of carotenoids. Our results indicate that some carnation cultivars can synthesize and accumulate esterified carotenoids. By manipulating the rate of biosynthesis and esterification of carotenoids in these cultivars, it should be feasible to produce novel carnation cultivars with vivid yellow flowers. [ABSTRACT FROM AUTHOR]

Astydamia latifolia is the only species of the genus Astydamia, which forms an early‐diverging lineage of Apiaceae, subfamily Apioideae. This species is subendemic to the Canary Islands and one of the most representative species of the coastal environments of this archipelago. Astydamia displays diplochory, that is, diaspores with two long‐distance dispersal (LDD) syndromes. In particular, A. latifolia has both anemochorous and thalassochorous fruit traits (corky and winged mericarps). Although we expect this species to have a high dispersal capacity, there is no genetic study addressing it. The divergence time of this species from its sister taxon is also unknown. In this study, we aimed (i) to unveil the phylogenetic relationships and divergence times of A. latifolia; (ii) to reconstruct its phylogeographic structure across the Canary Islands; and (iii) to estimate the number of inter‐island colonization events. To these ends, we first sequenced the internal transcribed spacer (ITS) region for A. latifolia, reconstructed the phylogenetic relationships of Astydamia and Apiaceae relatives and estimated divergence times. Then, two plastid DNA regions (psaI‐aacD and psbK‐trnS) were sequenced for 158 individuals (from 36 Canarian population and one NW African population) to reconstruct a haplotype network. The recently developed method Phylogeographic Analysis of Island Colonization Events (PAICE) was used to estimate the number of inter‐island colonization events. Results show that A. latifolia is a phylogenetically isolated lineage that diverged from the most closely related genus (Molopospermum) in the Eocene–Miocene. It displays a low plastid DNA diversity (only four haplotypes detected), which is accompanied by a high degree of haplotype sharing between islands and highly linear rarefaction curves of colonization obtained in PAICE. These findings suggest a high colonization ability for this species, most likely related to the availability of two LDD syndromes. [ABSTRACT FROM AUTHOR]

Since the introduction of the Oddy test in 1973, many museums and cultural institutions have put the method in use, developing their own versions and protocols. Currently the 3-in-1 version, temperature at 60 ºC and 2 g of tested material are set as common practice; however, other variables of the test are not standardized. The purpose of this study is to examine current versions of the Oddy test, to identify differences in the results derived from variations in the procedures, and ultimately raising awareness within the conservation community to work together towards a standardized protocol. In this article, we review the available information on the methodological differences in Oddy test protocols published in the literature related to glassware cleaning, coupon preparation, reaction vessel setup and rating of materials. Based on the review, and to highlight the many variables that could affect the results of the test, seven European cultural institutions working under the H2020 IPERION HS project performed a comparative 3-in-1 Oddy test by blindly evaluating the same ten materials. Each institution used its own test methodology but some guidelines were advised: (1) Detergents as a cleaning procedure for glassware, (2) P600 sandpaper or micromesh pad close to 1500 to prepare metal coupons and (3) 1:100 as water–air ratio. Despite this, differences between institutions' results were still observed. Some of them are due to the differences in the coupons preparation, either in the sanding pattern or in the edge area. In order to separate the contribution of the experimental setup and the subjectivity of the evaluation in the discrepancies, coupons from all institutions have been rated by a single team of judges with experience in the Oddy Test. Results show that differences in the evaluation criteria play a relevant role in the discrepancies of the results, especially for institutions with less experience in the test. These results highlight the need to further standardize the methodology and criteria for visual assessment. Nevertheless, the Oddy test has been found to be reliable for the identification of materials that produce emissions hazardous for the conservation of cultural assets. [ABSTRACT FROM AUTHOR]

During hemolysis, macrophages in the liver phagocytose damaged erythrocytes to prevent the toxic effects of cell-free hemoglobin and heme. It remains unclear how this homeostatic process modulates phagocyte functions in inflammatory diseases. Using a genetic mouse model of spherocytosis and single-cell RNA sequencing, we found that erythrophagocytosis skewed liver macrophages into an antiinflammatory phenotype that we defined as MarcohiHmoxhiMHC class IIlo erythrophagocytes. This phenotype transformation profoundly mitigated disease expression in a model of an anti-CD40-induced hyperinflammatory syndrome with necrotic hepatitis and in a nonalcoholic steatohepatitis model, representing 2 macrophage-driven sterile inflammatory diseases. We reproduced the antiinflammatory erythrophagocyte transformation in vitro by heme exposure of mouse and human macrophages, yielding a distinctive transcriptional signature that segregated heme-polarized from M1- and M2-polarized cells. Mapping transposase-accessible chromatin in single cells by sequencing defined the transcription factor NFE2L2/NRF2 as a critical driver of erythrophagocytes, and Nfe2l2/Nrf2 deficiency restored heme-suppressed inflammation. Our findings point to a pathway that regulates macrophage functions to link erythrocyte homeostasis with innate immunity. [ABSTRACT FROM AUTHOR]

In a previous study, two genes responsible for white flower phenotypes in carnation were identified. These genes encoded enzymes involved in anthocyanin synthesis, namely, flavanone 3-hydroxylase (F3H) and dihydroflavonol 4-reductase (DFR), and showed reduced expression in the white flower phenotypes. Here, we identify another candidate gene for white phenotype in carnation flowers using an RNA-seq analysis followed by RT-PCR. This candidate gene encodes a transcriptional regulatory factor of the basic helix-loop-helix (bHLH) type. In the cultivar examined here, both F3H and DFR genes produced active enzyme proteins; however, expression of DFR and of genes for enzymes involved in the downstream anthocyanin synthetic pathway from DFR was repressed in the absence of bHLH expression. Occasionally, flowers of the white flowered cultivar used here have red speckles and stripes on the white petals. We found that expression of bHLH occurred in these red petal segments and induced expression of DFR and the following downstream enzymes. Our results indicate that a member of the bHLH superfamily is another gene involved in anthocyanin synthesis in addition to structural genes encoding enzymes. [ABSTRACT FROM AUTHOR]

In any conservation project, conservators have to address several questions to design the appropriate intervention strategy. Among them, the effectiveness and duration of protective treatments is an important issue, not easy to evaluate. In the field of metallic cultural heritage, electrochemical techniques such as electrochemical impedance spectroscopy (EIS) can be used to evaluate patinas and protective coatings performance. Widely used in industrial applications, the use of these techniques in conservation science is much more recent and limited. During the restauration process of the bronze sphinxes at the main façade of the National Archaeological Museum in Madrid, collaboration with conservators has been established to test the performance of a recently developed gel-electrolyte cell for the electrochemical evaluation of metal cultural heritage. Electrochemical measurements (EIS and Rp) of the patinas have been carried out before, during and after the conservation treatments, on two different areas of the sculpture. This has provided information on how the protective coatings have improved corrosion resistance by 3 orders of magnitude, and how this protection is starting to decrease with time; periodic measurements will allow verifying the performance of the treatment over time and detecting the failure of the protection treatment before its effects are visible on the surface. [ABSTRACT FROM AUTHOR]

The voltammetry of immobilized particles methodology (VIMP) is used to characterize the composition of artificial patinas on copper. The voltammetric response of carbonate-, nitrate-, chloride-, sulfate-, and sulfide-based patinas is described using sub-microsamples attached to graphite electrodes in contact with aqueous acetate buffer. Patina-characteristic voltammetric profiles are obtained for the different artificial patinas that can be recognized using the generalized Tafel analysis of the voltammetric curves. VIMP data could also provide layer-by-layer information about composition and compactness/crystallinity of the patinas for which a simplified theoretical modeling is presented. • The voltammetry of immobilized particles methodology was used to study artificial patinas on copper and bronze. • Carbonate-, nitrate-, chloride-, sulfate-, and sulfide-based patinas are characterized by their voltammetric signatures. • In depth variation of the composition and compactness/crystallinity of the patinas is acquired. [ABSTRACT FROM AUTHOR]

Bioindication, evaluating biological responses to environmental disturbances, is crucial for assessing the ecological status of an ecosystem. While historical bioindication relied on macroscopic organisms, the introduction of environmental DNA (eDNA) techniques allows the application of protists without the necessity of morphological identification. In this study, we propose a novel bioindication methodology utilizing Arcellinida, a group of top predators among protists, as bioindicators of freshwater ecosystems. For that purpose, we first characterized the Arcellinida diversity over 1 year at three different points of Lake Sanabria, an ancient glacier lake known to be subjected to anthropogenic disturbances. We compared this diversity with an undisturbed control site. Second, we characterized the Arcellinida diversity in other ecosystems to generate the ecological background to test the connectivity between them. Results indicate limited connectivity between the different ecosystems and an edge effect between terrestrial and aquatic ecosystems. Disturbed freshwater ecosystems exhibited reduced Arcellinida diversity at both specific and infraspecific levels, providing valuable insight into recent disturbances. Arcellinida-based bioindication provides a sensitive, accurate and easy-to-interpret protocol for monitoring disturbances in freshwater ecosystems. It represents a valuable tool for environmental assessments and conservation strategies., (© 2024 The Author(s). Molecular Ecology Resources published by John Wiley & Sons Ltd.)

Environmental DNA-based diversity studies have increased in popularity with the development of high throughput sequencing technologies. This permits the potential simultaneous retrieval of vast amounts of molecular data from many different organisms and species, thus contributing to a wide range of biological disciplines. Environmental DNA protocols designed for protists often focused on the highly conserved small subunit of the ribosome gene, that does not permit species-level assignments. On the other hand, eDNA protocols aiming at species-level assignments allow a fine level ecological resolution and reproducible results. These protocols are currently applied to organisms living in marine and shallow lotic freshwater ecosystems, often in a bioindication purpose. Therefore, in this study, we present a species-level eDNA protocol designed to explore diversity of Arcellinida (Amoebozoa: Tubulinea) testate amoebae taxa that is based on mitochondrial cytochrome oxidase subunit I (COI). These organisms are widespread in lentic water bodies and soil ecosystems. We applied this protocol to 42 samples from peatlands, estuaries and soil environments, recovering all the infraorders in Glutinoconcha (with COI data), except for Hyalospheniformes. Our results revealed an unsuspected diversity in morphologically homogeneous groups such as Cylindrothecina, Excentrostoma or Sphaerothecina. With this protocol we expect to revolutionize the design of modern distributional Arcellinida surveys. Our approach involves a rapid and cost-effective analysis of testate amoeba diversity living in contrasted ecosystems. Therefore, the order Arcellinida has the potential to be established as a model group for a wide range of theoretical and applied studies., (© 2023 The Authors. Molecular Ecology Resources published by John Wiley & Sons Ltd.)

Materials such as wood, textiles, or plastics that are part of the exhibition system in museums are known to emit pollutants such as organic acids. Scientific and technical objects that include these materials in their composition can themselves be a potential source of emissions, which, together with inappropriate humidity and temperature conditions, can lead to corrosion of the metallic parts. In this work, we have studied the corrosivity of different locations in two venues of the Spanish National Museum of Science and Technology (MUNCYT). Coupons of the most representative metals from the collection were placed in different showcases and rooms for 9 months. The corrosion of the coupons has been evaluated in terms of the rate of mass gain, colour changes and characterisation of the corrosion products. The results were correlated to the relative humidity and concentration of gaseous pollutants to determine which metals are most susceptible to corrosion. The results show that metal artefacts exposed in showcases have a higher risk of corrosion than those exposed directly in the room, and that some pollutants are emitted by the artefacts. The corrosivity of the museum environment is low for copper, brass, and aluminium in most locations; however, some placements present a higher aggressivity for steel and lead, due to the high humidity and the presence of organic acids.

Introduction: BNT162b2 (BioNTech and Pfizer) is a nucleoside-modified mRNA vaccine that provides protection against SARS-CoV-2 infection and is generally well tolerated. However, data about its efficacy, immunogenicity and safety in people of old age or with underlying chronic conditions are scarce., Purpose: To describe BNT162b2 (BioNTech and Pfizer) COVID-19 vaccine immunogenicity, effectiveness and reactogenicity after complete vaccination (two doses), and immunogenicity and reactogenicity after one booster, in elders residing in nursing homes (NH) and healthy NH workers in real-life conditions., Methods: Observational, ambispective, multicenter study. Older adults and health workers were recruited from three nursing homes of a private hospital corporation located in three Spanish cities. The primary vaccination was carried out between January and March 2021. The follow-up was 13 months. Humoral immunity, adverse events, SARS-CoV-2 infections, hospitalizations and deaths were evaluated. Cellular immunity was assessed in a participant subset., Results: A total of 181 residents (mean age 84.1 years; 89.9% females, Charlson index ≥2: 45%) and 148 members of staff (mean age 45.2 years; 70.2% females) were surveyed (n:329). After primary vaccination of 327 participants, vaccine response in both groups was similar; ≈70% of participants, regardless of the group, had an antibody titer above the cut-off considered currently protective (260BAU/ml). This proportion increased significantly to ≈ 98% after the booster (p<0.0001 in both groups). Immunogenicity was largely determined by a prior history of COVID-19 infection. Twenty residents and 3 workers were tested for cellular immunity. There was evidence of cellular immunity after primary vaccination and after booster. During the study, one resident was hospitalized for SARS-CoV-2. No SARS-CoV-2-related deaths were reported and most adverse events were mild., Conclusions: Our results suggest that the BNT162b2 mRNA COVID-19 vaccine is immunogenic, effective and safe in elderly NH residents with underlying chronic conditions., (Copyright © 2023 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.)