Hollow-microsphere-integrated optofluidic immunochip for myocardial infarction biomarker microanalysis

This work developed an optofluidic immunochip that uses whispering gallery mode with fiber laser enhancement, for the rapid detection of a key biomarker cardiac troponin I for acute myocardial infarction (AMI). The immunochip adopted an innovative design, using perforated hollow glass microspheres (HGMS) as carriers, with antibodies immobilized on the inner surface of the HGMS, thereby achieving ultra-low sample consumption. The performance of the immunochip was improved by fiber laser, including spectral width compression to 0.019 nm, optical signal-to-noise ratio amplification to 63.17 dB, and an enhancement in the limit of detection to 5 pg/mL. Moreover, this immunochip can provide results within 15 min, making it highly suitable for early AMI risk management. Compared to the standard electrochemiluminescence detection method, although some differences exist in the results of the immunochip due to the principle of detection and differences in antibody affinity, its positive reference value can be calculated as 0.0754 ng/mL, with a successful recognition rate of 88% for positive patients. The immunosensor is integrated on a polydimethylsiloxane substrate, with a compact size suitable for use in point-of-care devices and AMI self-screening, as well as rapid disease screening and microanalysis of various biomarkers, offering new possibilities for applications in these fields.

Multi-Technique Characterization of 3.45 Ga Microfossils on Earth: A Key Approach to Detect Possible Traces of Life in Returned Samples from Mars

The NASA Mars 2020 Perseverance rover is actively exploring Jezero crater to conduct analyses on igneous and sedimentary rock targets from outcrops located on the crater floor (Máaz and Séítah formations) and from the delta deposits, respectively. The rock samples collected during this mission will be recovered during the Mars Sample Return mission, which plans to bring samples back to Earth in the 2030s to conduct in-depth studies using sophisticated laboratory instrumentation. Some of these samples may contain traces of ancient martian life that may be particularly difficult to detect and characterize because of their morphological simplicity and subtle biogeochemical expressions. Using the volcanic sediments of the 3.45 Ga Kitty's Gap Chert (Pilbara, Australia), containing putative early life forms (chemolithotrophs) and considered as astrobiological analogues for potential early Mars organisms, we document the steps required to demonstrate the syngenicity and biogenicity of such biosignatures using multiple complementary analytical techniques to provide information at different scales of observation. These include sedimentological, petrological, mineralogical, and geochemical analyses to demonstrate macro- to microscale habitability. New approaches, some unavailable at the time of the original description of these features, are used to verify the syngenicity and biogenicity of the purported fossil chemolithotrophs. The combination of elemental (proton-induced X-ray emission spectrometry) and molecular (deep-ultraviolet and Fourier transform infrared) analyses of rock slabs, thin sections, and focused ion beam sections reveals that the carbonaceous matter present in the samples is enriched in trace metals (e.g., V, Cr, Fe, Co) and is associated with aromatic and aliphatic molecules, which strongly support its biological origin. Transmission electron microscopy observations of the carbonaceous matter documented an amorphous nanostructure interpreted to correspond to the degraded remains of microorganisms and their by-products (extracellular polymeric substances, filaments…). Nevertheless, a small fraction of carbonaceous particles has signatures that are more metamorphosed. They probably represent either reworked detrital biological or abiotic fragments of mantle origin. This study serves as an example of the analytical protocol that would be needed to optimize the detection of fossil traces of life in martian rocks.

Micro-distribution of arsenic in toenail clippings using laser ablation inductively coupled plasma mass spectrometry: implications for biomonitoring

Toenails are a common monitoring tool for arsenic exposure, but the risk of external contamination of toenails has cast doubt on its usefulness. The main objective of this study is to investigate the micro-distribution of arsenic through the dorsoventral plane of nail clippings to understand endogenous vs exogenous sources. We used laser-ablation inductively coupled plasma mass spectrometry to measure arsenic through a dorsoventral cross-section of the nail plate collected from reference (N = 17) and exposed individuals (N = 35). Our main results showed (1) bulk toenail concentrations measured using ICP-MS in this study ranged from 0.54 to 4.35 µg/g; (2) there was a double-hump pattern in arsenic concentrations, i.e., dorsal and ventral layers had higher arsenic than the inner layer; (3) the double-hump was more pronounced in the exposed group (ventral: 6.25 μg/g; inner: 0.75 μg/g; dorsal: 0.95 μg/g) than the reference group (ventral: 0.58 μg/g; inner: 0.15 μg/g; dorsal: 0.29 μg/g) on average; (4) the distribution was, in part, associated with different binding affinity of nail layers (i.e., ventral > dorsal > inner); (5) most individuals in the higher exposure group showed > 25% contamination in ventral and dorsal nail layers; and (6) there were no statistically significant correlations between LA-ICP-MS arsenic with either bulk toenail arsenic or urine arsenic from the same individuals. Our results on micro-distribution and binding affinity provide insight into the impact of external contamination on arsenic concentrations and show how LA-ICP-MS can access the protected inner nail layer to provide a more accurate result.

Surface topography and spectrophotometric assessment of white spot lesions restored with nano-hydroxyapatite-containing universal adhesive resin: an in-vitro study

BACKGROUND

White spot lesion (WSL) is a main shortcoming accompanied by orthodontic treatment. It impairs the esthetic, surface hardness, and surface texture of enamel. So, this study was conducted to analyze the surface characteristics and color change of white spot lesions treated with nano-hydroxyapatite (nHA)-enriched universal adhesive resin.

MATERIALS AND METHODS

Eighty sound human permanent molars crowns were sectioned into two halves, producing 160 specimens. 16 specimens were left untreated, and 144 specimens were artificially-demineralized to generate WSLs. The specimens were classified according to the treatment approach applied as follows: I; Sound enamel, Group II; artificially-created WSLs, Group III; ICON resin-restored WSLs, Group IV; Universal adhesive resin-restored WSLs, Group V; 0.5 wt% nHA-containing universal adhesive resin-restored WSLs, Group VI; 1 wt% nHA-containing universal adhesive resin- restored WSLs, and Group VII; 3 wt% nHA-containing universal adhesive resin-restored WSLs, Group VIII; 5 wt% nHA-containing universal adhesive resin-restored WSLs, Group IX; 7 wt% nHA-containing universal adhesive resin-restored WSLs, and Group X; 10 wt% nHA-containing universal adhesive resin-restored WSLs. Some surface characteristics and color changes were assessed. Data was collected and analyzed statistically using ANOVA and the Tukey test at p < 0.05.

RESULTS

Surface microhardness of WSLs was significantly improved with all investigated ratios of nHA-containing universal adhesive (p < 0.0001), with the highest mean belonging to 10 wt% nHA-containing universal adhesive resin treated WSLs. All ratios of nHA-containing universal adhesive resin significantly reduced the surface roughness of WSLs (p < 0.0001). The investigated ratios of 1, 3, 5, 7, and 10 wt% nHA-containing universal adhesive resin treatment approach could mask the WSLs significantly (p < 0.0001).

CONCLUSIONS

Nano-hydroxyapatite-containing universal adhesive is a promising contemporary approach for the management of WSLs, coupled both the remineralizing concept and the minimally invasive resin infiltration.

Chemical Profile of Elements in the Stingless Bee Melipona scutellaris (Hymenoptera: Apidae: Meliponini) from Sites with Distinct Anthropogenic Activities

Stingless bees are pollinators in forests and crops that, during foraging, may be exposed to several environmental xenobiotics, including metallic elements. This study evaluated the presence of magnesium (Mg), aluminum (Al), calcium (Ca), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), arsenic (As), molybdenum (Mo), cadmium (Cd), barium (Ba), and lead (Pb) over the body surface of the stingless bee Melipona scutellaris visiting areas with different anthropogenic activity levels. The analyses were carried out using scanning electron microscopy with X-ray energy-dispersive spectroscopy (SEM/XEDS) and all tested elements were identified. Lead was the most abundant element in all samples, whereas Mn had the lowest abundance. High amounts of Cu and Zn were detected in the areas with metallurgic industries. The presence of metals on the body surface of this stingless bee varied according to the level of human activities in the studied areas.

Associations of maternal postpartum depressive and anxiety symptoms with 4-month infant and mother self- and interactive contingency of gaze, affect, and touch

Maternal depression and anxiety are associated with infant and mother self- and interactive difficulties. Although maternal depression and anxiety usually co-occur, studies taking this comorbidity into account are few. Despite some literature, we lack a detailed understanding of how maternal depressive and anxiety symptoms may be associated with patterns of mother-infant interaction. We examined associations of maternal postpartum depressive and anxiety symptoms with infant and mother self- and interactive patterns by conducting multi-level time-series models in a sample of 56 Turkish mothers and their 4-month infants. Time-series models assessed the temporal dynamics of interaction via infant and mother self- and interactive contingency. Videotaped face-to-face interaction was coded on a 1s time base for infant and mother gaze and facial affect, infant vocal affect, and mother touch. Results indicated that mothers with high depressive symptoms were vulnerable to infants looking away, reacting with negative touch; their infants remained affectively midrange, metaphorically distancing themselves from mothers' affect. Mothers with high anxiety symptoms were vulnerable to infants becoming facially dampened and mothers reacted with negative facial affect. Altered infant and mother self-contingency patterns were largely opposite for maternal depressive and anxiety symptoms. These patterns describe foundational processes by which maternal postpartum mood is transmitted to the infant and which may affect infant development.

Mineralogical and dimensional characterization of EMPs destined for biological experimentation

Mineral specimens and mineral reference materials should be understood to be mixtures of various mineral species and the properties of each individual species will likely represent a range of quantifiable values and qualitative characteristics. The use of incompletely characterized mineral specimens may introduce significant uncontrolled variables in any experiment. Any mineral characterization should include an understanding of the bulk properties of the specimen as well as microanalytical and crystallographic characterization of individual mineral phases. This characterization should comprise a range of length scales to accommodate naked-eye level observations up to electron microscopic observations and analyses. Large spatial scale observations are useful to describe the physical properties of the material and understand the scale of inhomogeneities that may be present in a mineral sample. Microanalysis provides critical compositional and crystallographic information for mineral identification. It is critical to recognize where gaps might exist in the data produced during the characterization of a material and if those gaps are critical to evaluating the effect those minerals might have on the result of a given experiment. Likewise, it is critical to understand the interplay of various minerals that might be present in a sample other than the specific mineral of interest. The accessory minerals that are present, even if only trace amounts, could have a major impact and need to be isolated, or their impact accounted for in the interpretation of results. Dimensional characterization of particulate produced from a mineral specimen is important, but not as simple a task as it might appear. Dimensional data can be produced through any of several microscopic techniques, each with specific limitations and potential to be biased due to sample preparation technique. This understanding of the full composition of a mineral specimen cannot be obtained through rudimentary examination and it cannot be taken for granted that it has been performed by the supplier of the specimen.

Fabrication and application of Zn5 functionalized copolymer monolithic column for pipette tip micro-solid phase extraction of 4 polycyclic aromatic hydrocarbons in edible oil

The contamination of polycyclic aromatic hydrocarbons (PAHs) in edible oil is a health threat. Thus, trace analysis of PAHs is of high necessity. Based on the efficient adsorption of PAHs on Zn₅ metal cluster, a Zn₅ functionalized copolymer monolithic column was rationally designed for pipette tip micro-solid phase extraction (μ-SPE). The modified Zn₅ improved the adsorption selectivity and capacity of the monolith for naphthalene, phenanthrene, fluoranthene and pyrene. Chemical doping and copolymerization stabilized the monolith with a long life. Under optimal extraction conditions, a μ-SPE-high performance liquid chromatography with ultraviolet detector method was established for the detection of 4 PAHs in edible oils. The method yielded detection ranges of 0.15-250 μg L^-1 (R² > 0.997), detection limits of 0.050-1.5 μg L^-1, satisfactory recoveries (86.3-101.5 %), and high precisions (RSDs < 7.9 %). The results indicated that the Zn₅ functionalized copolymer monolithic column was an ideal separation medium for the detection of PAHs residues in edible oils.

The vocal dialogue in 9/11 pregnant widows and their infants: Specificities of co-regulation

Mothers who were pregnant and widowed on September 11, 2001, and their 4-6-month infants (in utero on 9/11) were filmed during face-to-face interaction and their vocal dialogues were examined via microanalysis. Mothers were White, well-educated, mean age 34.3 years, and far from the World Trade Center site on 9/11; infants were 4-6 months, half female. We examined the bi-directional, moment-by-moment co-regulation of the timing of vocal dialogue, and particularly turn taking, in mother-infant and stranger-infant interactions, with time-series models. We analyzed the contingent coordination of durations of (1) vocalizations of the turn-holder, and (2) switching-pauses at the moment of the turn exchange. The switching pause is an aspect of the rhythm of the turn-holder who, after taking a turn, yields the floor to the partner through the switching pause. Turn taking is the lynchpin of dialogue, and the bi-directional contingent coordination of the switching-pause regulates the turn exchange. Both partners showed signs of risk and resilience. The 9/11 mothers did not coordinate the timing of turn taking with their infants, a highly unusual finding. In contrast, the 9/11 infants did coordinate the timing of turn taking with their mothers, and with the "stranger," forms of resilience. We propose that the 9/11 mother's difficulty coordinating with the infant's turn taking rhythm is a mode of transmission of her trauma to the infant. This work expands our knowledge of the specificities of co-regulation in the context of the 9/11 trauma.

Geochemical and mineralogical characterization of phosphogypsum and leaching tests for the prediction of the mobility of trace elements

Phosphoric acid manufacturing generates large amounts of phosphogypsum (PG); a by-product generally disposed in the surface or evacuated in the seawater without any pretreatment. Phosphogypsum may host non-negligible amounts of valuable elements such as rare earth elements (REEs), which are critical elements on the global market. Surface disposal of PG may be a sustainable option to allow further processing in order to recover valuable elements. However, surface disposal exposes PG to atmospheric conditions (e.g., water, oxygen) which may increase their reactivity and accelerate the release rate of chemical species. This study aims to evaluate the trace element release rate from PG at atmospheric conditions. The studied PG samples were collected from a Moroccan phosphate treatment plant. The samples were characterized for their (i) chemical composition using inductively coupled plasma optical emission spectrometry (ICP-OES) for major elements and inductively coupled plasma mass spectrometry (ICP-MS) for trace elements; (ii) mineralogical composition by X-ray diffraction (XRD), scanning electron microscope equipped with energy-dispersive spectrometer (SEM-EDS), laser-induced breakdown spectroscopy (LIBS), and the mineral chemical composition was analyzed by electron probe microanalyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS); and (iii) chemical species release rate using leaching tests over 24 h at 25 and 60 °C. Chemically, the PG samples were mainly composed of Ca (23.03-23.35 wt.%), S (17.65-17.71 wt.%), and Si (0.75-0.82 wt.%), and non-negligible amounts of trace elements: REE (344-349 ppm), Cd (3.5-7.4 ppm), U (9.3-27.4 ppm). Mineralogically, the PGs are mainly formed by gypsum (94.2-95.9 wt.%) and quartz (1.67-1.76 wt.%). In terms of chemical species release, the PGs showed a higher reactivity at 60 °C compared to room temperature with a higher release rate at the beginning of the leaching tests. Quantitatively, the PG samples released 3.57-4.11 µg/L/day of REE, 3.18-17.29 µg/L/day of U, and 1.67-5.49 µg/L/day of Cd. Based on the leaching results, we concluded that the trace elements (e.g., U, Cd, REE) are incorporated in PG crystal lattice, which may explain their low concentrations in the leachates. Consequently, total digestion of PG matrix is required to solubilize REE.

Abundance and fate of glass microspheres in river sediments and roadside soils: Lessons from the Świętokrzyskie region case study (south-central Poland)

Traffic-related glass microspheres in fluvial and roadside soil settings were used as an indicator for the occurrence and extent of road dust as a source of emissions. Microspheres were found in sediments of two rivers, at a distance of approximately 25 km of the city of Kielce (south-central Poland). Their highest contents in sediments were recorded near street stormwater drains into the Silnica River flowing through the city. The study also showed no influence of local bridges on the spatial distribution of glass microspheres in the river deposits. In contrast, soils adjacent to a two-lane highway revealed the presence of microspheres as far as 60 m of the roadway. As opposed to other road dust components, which have commonly been applied in traffic contamination studies, glass microspheres were a good indicator for road dust contamination. Most microspheres showed diverse concentrations of all minor and trace metal(loid)s. The mean contents of As, Pb and Sb (n = 601) were: 0.003 wt%, 0.014 wt% and 0.010 wt%, respectively, and only in some microspherules these elements exceeded EU current/expected regulatory standard levels (0.02%/0.015% for each). Although generally considered to be non-toxic, silica rich microbeads might be the best proxy for non-exhaust particle matter discharged from the road traffic into the environment.

Strength and durability performance of modified cement-based concrete incorporated immobilized bacteria

Owing to the load bearing and the other external environmental factors, the defects in the concrete occur in the form of cracks and flaws which leads to the reduction in the durability characteristics. Generally, the bacteria-based autogenous healing is adopted to restore those cracks. The ureolytic bacteria used urea as a source of nitrogen and convert it to carbonate ions, and then carbonate ions react with calcium ions to induce calcium carbonate in the presence of water. In the present study, binary cement-based concrete containing different concentration of immobilized bacteria is investigated, and its performance is evaluated based on the strength and durability characteristics. The experimentation includes bagasse ash (< 45µ) and fly ash (Class C) in proportions partially blended with cement. External loads are stimulated to assess the mechanical properties of concrete. Rapid chloride penetration test of the concrete before the induction of cracks is also performed. By comparing the compression test results, the microbial concrete of 10⁵cells/mg shows greater compressive strength when compared with the microbial concrete of 10⁷cells/mg and also with the conventional concrete. SEM analysis and compression test results reveal 15% fly ash additives have accomplished microbial concrete. And also the test results indicate the potential of encapsulation using clay pellets and silica gel.

Field study on the characteristics of scales in damaged multi-material water supply pipelines: Insights into heavy metal and biological stability

Microbial corrosion and heavy metal accumulation in metal water supply pipelines aggravate scale formation and may result in pipeline leakage or bursting events. To better understand the corrosion and corrosion products in the damaged pipes, deposits excavated from three damaged pipes after 22-26 year service periods were analyzed. Using a combination of advanced micro-mineral techniques and 16S rRNA high-throughput sequencing, the micromorphology, chemical composition, and bacterial community were investigated systematically. Unlined pipe wall scales ruptured while lined pipes leaked due to joint scales. Dendrogram correlation results demonstrated that V/As, Al/Pb, and Cr/Mn clusters exhibited co-adsorption and co-precipitation characteristics. FTIR and XRD analysis detected the presence of γ-FeOOH, α-FeOOH in loose scales, and Fe₃O₄ in rigid scales. Scales were colonized by various corrosion bacteria, with sulfate reducing bacteria and ammonia producing bacteria being dominant in the scales of anticorrosive and non-corrosive pipe, respectively. Tl, Ca, Al, and Pb exhibited an extremely positive correlation with Rhodocyclaceae, Ferritrophicum, Thermodesulfovibrionia, and Clostridiaceae. Al and V presented a potential Hazard Quotient risk to consumers, while Cd was potentially bioavailable in all inner scales. Overall, this study provides valuable information for the effective management and avoidance of corrosion-induced pipeline damage and heavy metal release.

Glass microspheres in road dust of the city of Kielce (south-central Poland) as markers of traffic-related pollution

Glass microspheres are widely used as reflective components in road and pavement marking materials. They commonly occur in road dust mixed with different particles of anthropogenic and geogenic origin. This paper describes different methods that enable discrimination of glass microspheres from other morphologically similar particles that occur in road dust of Kielce. The individual glass microspheres vary from 30 to 1350 µm in diameter and consist of recycled Ca-, Na-, Mg-silica glass with a minor admixture of Al, Fe, K and S. Because of their stability and chemical composition, glass microspheres are good markers of traffic-related pollution in different environmental archives. Of different elements present in Kielce road dust, the fraction < 0.125 mm was distinctly abundant in zirconium, the main constituent of disk brakes or brake pads and a potential marker of road traffic pollution. However, the statistically significant positive correlation of the Si-Zr pair (R = 0.54) in the 1.0-2.0 mm fraction is linked to the presence of some detritic quartz grains with zircon inclusions. The other metals determined provide ambiguous traffic-related signatures and may be derived from different pollution sources.

Advances in microanalysis: Magnifying the social microscope on mother-infant interactions

Microanalysis is a method for recording and coding interactional behavior. It has been often compared to a social microscope, for its power in detailing the second-by-second dynamics of social interaction. Microanalysis has deep multidisciplinary foundations, that privilege the description of interactions as they naturally occur, with the purpose of understanding the relations between multiple and simultaneous streams of behaviors. In developmental science, microanalysis has uncovered structural and temporal elements in mother-infant interactions, improving our understanding of the effects of mother-infant interpersonal adaptation in the infant's cognitive and social-emotional development. Detailed manual coding is time intensive and resource demanding, imposing restrictions to sample size, and the ability to analyze multiple behavioral modalities. Moreover, recent increases in the density of multivariate data require different tools. We review present-day techniques that tackle those challenges: (1) sensing techniques for motion tracking and physiological recording; (2) exploratory techniques for detecting patterns from high-density data; and (3) inferential and modeling techniques for understanding contingencies between interactional time series. Two illustrations, from recent developmental research, reveal the power of bringing new lenses to our social microscope: (1) egocentric vision, the use of head mounted cameras and eye-trackers in capturing the infant's first-person perspective of a social exchange; and (2) daily activity sensing, wearable multimodal sensing that brought mother-infant interaction research to the environments where it naturally unfolds.

The cono-dos and cono-dont's of phosphatic microfossil preparation and microanalysis

Scanning electron microscope (SEM) imaging of fossils allows unlocking ultrastructural information about their skeletal tissues, but sample preparation of biominerals forming their skeletons requires time, patience, and knowledge. SEM and associated analytical methods allow the observation of internal microstructure, shedding light on function, growth and chemistry. Sample preparation is the process by which material is fixed within a medium (e.g. epoxy resin), a transect created and surface defects removed. This step is arguably the most important in any SEM-based analysis, allowing for the acquisition of reliable, high quality data sets. When conducting any SEM-based technique, the presence of a flat surface is needed to collect consistent and reliable data. Surfaces with topography will both induce charging effects but will also compromise the reliability of data acquired. Techniques from material science are continuously adapted to palaeontological applications, in particular with respect to calcareous microfossils. However, similar studies have not been extensively conducted on bioapatite, owing in part to the difficulties faced in sample preparation alongside its susceptibility to electron beam damage. This case study focuses on conodonts, a marine vertebrate group ranging from the late Cambrian to the Late Triassic. They have been chosen as a model due to the abundance of material, complexity of internal tissues and previous work focused on histological features. With these phosphatic microfossils, we attempt to outline the process of sample preparation and provide information on how to avoid and overcome common pitfalls.

Do tree rings record changes in soil fertility? Results from a Quercus petraea fertilization trial

Through the variations in their dimension, density, anatomy or isotopes composition, tree rings have provided invaluable proxies to evaluate past changes in the environment. Whereas long-term records of changes in soil fertility are particularly desired for forest ecosystem studies, the use of the chemical composition of tree rings as potential marker is still controversial. Dendrochemistry has sometimes been considered as a promising approach to study past changes in soil chemistry, whereas some authors stated that element translocations in the wood preclude any possibility of reliable retrospective monitoring. Here, we aimed at testing whether the wood elemental content of fertilized oaks (Quercus petraea) differed from control trees >30 years after a NPKCaMg fertilization and, if so, if the date of fertilization could be retrieved from the ring analysis. The contents in N, Mg, P, K, Ca and Mn were measured for each of the 43 sampled trees and in every ring of the 58-year long chronology with a non-destructive method coupling a Wavelength Dispersive Spectroscope (WDS) with a Scanning Electron Microscope (SEM). The results showed significantly higher contents in Ca and lower contents in Mn in fertilized compared to control trees. However, there was no difference in elemental content between the rings of the fertilized trees built in the 20 years before and those built after fertilization. Thus, whereas the effect of fertilization on increasing ring width was dramatic, immediate and relatively short-lasting, the elemental composition of the entire ring sequence was impacted, precluding the dating of the event. These results question the possibility to reconstruct long-term changes in soil fertility based on dendrochemistry.

Spectroscopic analysis of XIV century wall paintings from Patriarchate of Peć Monastery, Serbia

The Church of the Holy Mother of God Hodegetria in Peć is decorated with wall paintings that date from the beginning of the 14th century. In terms of style they correspond to Byzantine wall paintings from the epoch of Paleologos. The painting technique and pigment pallete has been examined on micro fragments in thin cross-sections by means of optical microscopy (OM), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and micro- Raman spectroscopy. Use of the fresco technique and two supporting plaster layers was noted on the majority of samples, while in large blue painted areas, a combination of fresco and secco techniques was used. The SEM-EDS results showed the presence of Ca as the main component of plaster besides the traces of Si and Mg. In some samples egg white as a binder was identified. The paint film is often multilayered. Twelve pigments were identified, mainly natural earth pigments such as red ochre, yellow ochre and green earth. A mixture of pigments was used for attaining desirable optical and aesthetical impressions. As decay product only weddelite was detected in many preparatory and painted samples.

Diagnosis of electrocution: The application of scanning electron microscope and energy-dispersive X-ray spectroscopy in five cases

INTRODUCTION

Deaths from electricity, generally, do not have specific findings at the autopsy. The diagnosis is commonly based on the circumstances of the death and the morphologic findings, above all the current mark. Yet, the skin injury due to an electrocution and other kinds of thermal injuries often cannot be differentiated with certainty. Therefore, there is a great interest in finding specific markers of electrocution. The search for the metallization of the skin through Scanning Electron Microscope equipped with Energy Dispersive X-Ray Spectroscopy (EDS) probe is of special importance in order to achieve a definite diagnosis in case of suspected electrocution.

MATERIALS AND METHODS

We selected five cases in which the electrocution was extremely likely considering the circumstances of the death. In each case a forensic autopsy was performed. Then, the skin specimens were stained with Hematoxylin Eosin and Perls. On the other hand, the skin lesions were examined with a scanning electron microscope equipped with EDS probe in order to evaluate the morphological ultrastructural features and the presence of deposits on the surface of the skin.

RESULTS

The typical skin injury of the electrocution (current mark) were macroscopically detected in all of the cases. The microscopic examination of the skin lesions revealed the typical spherical vacuoles in the horny layer and, in the epidermis, the elongation of the cell nuclei as well as necrosis. Perls staining was negative in 4 out 6 cases. Ultrastructural morphology revealed the evident vacuolization of the horny layer, elongation of epidermic cells, coagulation of the elastic fibers.

EDS-MICROANALYSIS

In the specimens collected from the site of contact with the conductor of case 1 and 2, the presence of the Kα peaks of iron was detected. In the corresponding specimens taken from cases 2, 4, 5 the microanalysis showed the Kα peaks of titanium. In case 3, titanium and carbon were found.

CONCLUSIONS

In the suspicion of electrocution, the integrated use of different tools is recommended, including macroscopic observation, H&E staining, iron-specific staining, scanning electron microscopy and EDS microanalysis. Only the careful interpretation of the results provided by all these methods can allow the pathologist to correctly identify the cause of the death. Particularly, the present study suggests that the microanalysis (SEM-EDS) represents a very useful tool for the diagnosis of electrocution, allowing the detection and the identification of the metals embedded in the skin and their evaluation in the context of the ultrastructural morphology.

The perils of information giving: What an accidental incident taught us about messages and roles

INTRODUCTION

Occasionally mishaps in an investigation lead to new understandings. We report how a videotaped emotional discussion among a family after they had received information about their relative's state gave us insight into the minute sources of uncertainty that fueled their confusion.

METHODS

Based on the themes of the family's discussion, we used a forensic approach to locate distinct sequences of interest in the video and transcript. Microanalysis of face-to-face dialogue was performed to understand the most critical sequence. The analysis was supported by questionnaire data.

RESULTS

The family's disagreement about the patient's prognosis could be traced to minor differences in how the surgeon and the anesthesiologist had framed the information. In attempting to resolve apparent contradictions, the family realized they were uncertain about the physicians' roles, which amplified the emotional expressions in the discussions. Role confusion could be traced to subtle details in the surgeon's presentation of himself and the surgery.

CONCLUSION

Minor discrepancies in how health care professionals frame information combined with not exploring relatives' emotions may lead to major differences in relatives' perceptions. Doubt about health providers' roles decontextualizes information and reassurance, magnifying uncertainty.

PRACTICE IMPLICATIONS

Health providers should present themselves clearly without haste. If more than one provider is involved, joint preparation of the main messages may be necessary.

Atmospheric particulate matter intercepted by moss-bags: Relations to moss trace element uptake and land use

Particulate matter has to be constantly monitored because it is an important atmospheric transport form of potentially harmful contaminants. The cost-effective method of the moss-bags can be employed to evaluate both loads and chemical composition of PM. PM entrapped by the moss Pseudoscleropodium purum exposed in bags in 9 European sites was characterized for number, size and chemical composition by SEM/EDX. Moreover, moss elemental uptake of 53 elements including rare earth elements was estimated by ICP-MS analysis. All above was aimed to find possible relations between PM profile and moss uptake and to find out eventual element markers of the different land use (i.e. agricultural, urban, industrial) of the selected sites. After exposure, about 12,000 particles, mostly within the inhalable fraction, were counted on P. purum leaves; their number generally increased from the agricultural sites to the urban and industrial ones. ICP analysis indicated that twenty-three elements were significantly accumulated by mosses with different element profile according to the various land uses. The PM from agricultural sites were mainly made of natural/crustal elements or derived from rural activities. Industrial-related PM covered a wider range of sources, from those linked to specific industrial activities, to those related to manufacturing processes or use of heavy-duty vehicles. This study indicates a close association between PM amount and moss element-uptake, which increases in parallel with PM amount. Precious metals and REEs may constitute novel markers of air pollution in urban and agricultural sites, respectively.

Organic Matter in Cosmic Dust

Organics are observed to be a significant component of cosmic dust in nearly all environments were dust is observed. In many cases only remote telescope observations of these materials are obtainable and our knowledge of the nature of these materials is very basic. However, it is possible to obtain actual samples of extraterrestrial dust in the Earth's stratosphere, in Antarctic ice and snow, in near-Earth orbit, and via spacecraft missions to asteroids and comets. It is clear that cosmic dust contains a diverse population of organic materials that owe their origins to a variety of chemical processes occurring in many different environments. The presence of isotopic enrichments of D and 15N suggests that many of these organic materials have an interstellar/protosolar heritage. The study of these samples is of considerable importance since they are the best preserved materials of the early Solar System available.

Miniaturized and direct spectrophotometric multi-sample analysis of trace metals in natural waters

Trends in the analysis of trace metals in natural waters are mainly based on the development of sample treatment methods to isolate and pre-concentrate the metal from the matrix in a simpler extract for further instrumental analysis. However, direct analysis is often possible using more accessible techniques such as spectrophotometry. In this case a proper ligand is required to form a complex that absorbs radiation in the ultraviolet-visible (UV-Vis) spectrum. In this sense, the hydrazone derivative, di-2-pyridylketone benzoylhydrazone (dPKBH), forms complexes with copper (Cu) and vanadium (V) that absorb light at 370 and 395 nm, respectively. Although spectrophotometric methods are considered as time- and reagent-consuming, this work focused on its miniaturization by reducing the volume of sample as well as time and cost of analysis. In both methods, a micro-amount of sample is placed into a microplate reader with a capacity for 96 samples, which can be analyzed in times ranging from 5 to 10 min. The proposed methods have been optimized using a Box-Behnken design of experiments. For Cu determination, concentration of phosphate buffer solution at pH 8.33, masking agents (ammonium fluoride and sodium citrate), and dPKBH were optimized. For V analysis, sample (pH 4.5) was obtained using acetic acid/sodium acetate buffer, and masking agents were ammonium fluoride and 1,2-cyclohexanediaminetetraacetic acid. Under optimal conditions, both methods were applied to the analysis of certified reference materials TMDA-62 (lake water), LGC-6016 (estuarine water), and LGC-6019 (river water). In all cases, results proved the accuracy of the method.

The study of Triadic Family Interactions: the Proposal of an Observational Procedure

In the present article we provide an analytical review of 26 recent studies, which investigated triadic mother-father-child interactions through observational procedures. We focused on the methodological framework and compared the studies according to different criteria, in order to highlight the complexity of the object of study as well as the variety of dimensions and measures that have been used. Even if all the considered studies were designed to analyze triads, very few used coherently triadic categories; most of them focused on the individual members of the triad or on the parents with respect to the child. Joining the research that have stressed the importance of focusing on the reciprocal interactions of all members of the triad, we propose a methodological procedure that allows to describe the triad as a system without losing sight of the single participants and the simultaneity, interdependence, and processuality of their actions.

Non-destructive micro-analytical differentiation of copper pigments in paint layers of works of art using laboratory-based techniques

An unambiguous identification of pigments in paint layers of works of art forms a substantial part of the description of a painting technique, which is essential for the evaluation of the work of art including determination of the period and/or region of its creation as well as its attribution to a workshop or an author. Copper pigments represent a significant group of materials used in historic paintings. Because of their substantial diversity and, on the other hand, similarity, their identification and differentiation is a challenging task. An analytical procedure for unambiguous determination of both mineral-type (azurite, malachite, posnjakite, atacamite, etc.) and verdigris-type (copper acetates) copper pigments in the paint layers is presented, including light microscopy under VIS and UV light, electron microscopy with elemental microanalysis, Fourier transformed infrared micro-spectroscopy (micro-FTIR), and X-ray powder micro-diffraction (micro-XRD). Micro-Raman measurements were largely hindered by fluorescence. The choice of the analytical methods meets the contemporary requirement of a detailed description of various components in heterogeneous and minute samples of paint layers without their destruction. It is beneficial to use the combination of phase sensitive methods such as micro-FTIR and micro-XRD, because it allows the identification of both mineral-type and verdigris-type copper pigments in one paint layer. In addition, preliminary results concerning the study of the loss of crystallinity of verdigris-type pigments in proteinaceous binding media and the effect of lead white and lead tin yellow as highly absorbing matrix on verdigris identification in paint layers are reported.

Non-destructive analyses on a meteorite fragment that fell in the Madrid city centre in 1896

The historical Madrid meteorite chondrite fell in 1896 showing thin melt veins with a 65% of brecciated forsterite fragments surrounded by a fine grained matrix formed by troilite, chromite and Fe-Ni blebs. It exhibits a delicate iron infill, neo-formation of troilite in pockets and shock veins and neo-formation of Na-feldspar formed at high temperature and fast quenching. The semi-quantitative mineral determinations were performed with IMAGEJ freeware and chemical mappings resulting in the following approximated compositions: olivine (~55%); augite (~10%); enstatite (~10%); plagioclase (~10%); chromite (~2%); troilite (~4%), kamacite-taenite α-γ-(Fe, Ni) (~7%) and merrillite (~7%). The specimen was also studied by computer tomography, micro-Raman spectroscopy and spectral cathodoluminescence. X-ray diffraction patterns were also recorded in non-destructive way on a polished surface because of the small size of the specimen. This combination of non-destructive techniques provides an improved knowledge on the Madrid-1896 meteorite compared to the previous study performed on the same specimen carried out twenty years ago by electron probe microanalysis and optical microscopy in destructive way. Limits of these techniques are the specimen's size in the analytical chambers and the threshold resolution of the microscopes analyzing shock veins micro-crystals.