Absolute Concentrations Research Articles

The first human normative ranges and biomarker performance of dimethylguanidino valeric acid isoforms in fatty liver disease

We have recently determined dimethylguanidino valeric acid (DMGV) to be a novel biomarker of liver injury in non-alcoholic fatty liver disease (NAFLD) and an independent predictor of incident diabetes over a decade in advance. DMGV consists of two stereo-isomers, asymmetric dimethylguanidino valeric acid (ADGV) and symmetric dimethylguanidino valeric acid (SDGV). Here we report, for the first time, the upper limits of normal of both isomers in humans at the accepted 5.56% liver fat threshold for NAFLD, determined using invivo magnetic resonance spectroscopy. We performed independent and blinded comparative analyses of ADGV and SDGV levels using two different liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods in (A) our laboratory, and (B) the New South Wales Chemical Pathology state laboratory, using unique columns, LC-MS/MS equipment, extraction protocols and normalisation approaches. Despite these differences, each laboratory reported consistent absolute concentrations across a range of liver fat percentages. We next determined the diagnostic performance of SDGV compared to ADGV in a cohort of 268 individuals with liver fat measurements. In derivation-validation analyses we determined rule-in/rule-out thresholds and the concentration of SDGV that provides optimal performance across sensitivity and specificity for the identification of NAFLD. In conclusion, we have herein determined for the first time the true human plasma reference range of both isoforms of an emerging novel biomarker of NAFLD, at the accepted upper normal threshold of liver fat. We have also identified that SDGV is the isoform with the best diagnostic performance and determined the optimal cut-point for its detection of NAFLD.

Ultrasensitive and High-Resolution Protein Spatially Decoding Framework for Tumor Extracellular Vesicles.

Proteins localized on the surface or within the lumen of tumor-derived extracellular vesicles (EVs) play distinct roles in cancer progression. However, quantifying both populations of proteins within EVs has been hampered due to the limited sensitivity of the existing protein detection methods and inefficient EV isolation techniques. In this study, the eSimoa framework, an innovative approach enabling spatial decoding of EV protein biomarkers with unmatched sensitivity and specificity is presented. Using the luminal eSimoa pipeline, the absolute concentration of luminal RAS or KRASG12D proteins is released and measured, uncovering their prevalence in pancreatic tumor-derived EVs. The pulldown eSimoa pipeline measured absolute protein concentrations from low-abundance EV subpopulations. The eSimoa assays detected EVs in both PBS and plasma samples, confirming their applicability across diverse clinical sample types. Overall, the eSimoa framework offers a valuable tool to (1) detect EVs at concentrations as low as 105 EVmL-1 in plasma, (2) quantify absolute EV protein concentrations as low as fM, and (3) decode the spatial distribution of EV proteins. This study highlights the potential of eSimoa in identifying disease-specific EV protein biomarkers in clinical samples with minimal pre-purification, thereby driving advancements in clinical translation.

Prevalence of Multistationarity and Absolute Concentration Robustness in Reaction Networks

Prevalence of Multistationarity and Absolute Concentration Robustness in Reaction Networks

Comparative analysis of kinetic realizations of insulin signaling

Several studies have developed dynamical models to understand the underlying mechanisms of insulin signaling, a signaling cascade that leads to the translocation of glucose, the human body’s main source of energy. Fortunately, reaction network analysis allows us to extract properties of dynamical systems without depending on their model parameter values. This study focuses on the comparison of insulin signaling in healthy state (INSMS or INSulin Metabolic Signaling) and in type 2 diabetes (INRES or INsulin RESistance) using reaction network analysis. The analysis uses network decomposition to identify the different subsystems involved in insulin signaling (e.g., insulin receptor binding and recycling, GLUT4 translocation, and ERK signaling pathway, among others). Furthermore, results show that INSMS and INRES are similar with respect to some network, structo-kinetic, and kinetic properties. Their differences, however, provide insights into what happens when insulin resistance occurs. First, the variation in the number of species involved in INSMS and INRES suggests that when irregularities occur in the insulin signaling pathway, other complexes (and, hence, other processes) get involved, characterizing insulin resistance. Second, the loss of concordance exhibited by INRES suggests less restrictive interplay between the species involved in insulin signaling, leading to unusual activities in the signaling cascade. Lastly, GLUT4 losing its absolute concentration robustness in INRES may signify that the transporter has lost its reliability in shuttling glucose to the cell, inhibiting efficient cellular energy production. This study also suggests possible applications of the equilibria parametrization and network decomposition, resulting from the analysis, to potentially establish absolute concentration robustness in a species.

Multi-line OH-LIF for gas-phase temperature and concentration imaging in the SpraySyn burner

Gas-phase temperature and OH concentration images are measured in the SpraySyn nanoparticle-synthesis standard burner using multi-line OH laser-induced fluorescence (LIF) thermometry. In this burner, a spray flame fed by a combustible nanoparticle precursor solution is stabilized by a surrounding axisymmetric lean premixed laminar methane/oxygen pilot flame. For measuring OH rotational temperature, the laser is scanned across the 282.05–282.17 nm range and LIF excitation spectra are fitted for each image pixel by simulated spectra. Temperature maps are determined for the pilot flame and the ethanol spray flame with variable dispersion gas flow rates of oxygen used in the two-fluid nozzle. The addition of 2-EHA (2-ethylhexanoic acid) to the solution was found to increase the flame temperature. Laser attenuation across the flame was measured using simultaneous recordings of the fluorescence of uranine/water solution from two dye cuvettes illuminated with the laser sheet before and after the flame and the effect of attenuation was quantified. Absolute OH concentration distributions are determined by combining the LIF images, laser attenuation measurements, and derived temperature distributions. The temporal stability of the flame is investigated for various operating conditions by statistical evaluation of recorded instantaneous OH-LIF images.

Generating a Sustained Oxygen-Stable Atomic Concentration in a High-Temperature Gas Effect Investigation.

Modulated laser absorption spectroscopy is an ideal technique for evaluating flow-field parameters and determining flow-field quality by measuring the atoms dissociated in high-temperature environments. However, to obtain the absolute number density of atoms in the flow field, it is necessary to compare the measured modulated absorption spectroscopy signal with a known atomic concentration and establish a quantitative relationship through concentration calibration. Nevertheless, it remains a challenging task to prepare transient atomic samples with known concentrations that meet the calibration requirements. This study utilized the alternating-current glow discharge technique to dissociate oxygen in the air flow, resulting in the continuous generation of oxygen atoms. The absolute number densities of the generated oxygen atoms were determined by measuring the direct absorption spectra of centered on 777 nm for oxygen atoms. The number densities of the generated atoms were finely tuned by adjusting the discharge parameters. Throughout the 120-min continuous operation of the discharge system, the concentration of excited-state oxygen atoms remained stable within the range of (2.51 ± 0.02) × 108 cm-3, demonstrating the remarkable stability of the transient atomic concentration generated by the glow discharge plasma. This observation suggests that the generated atoms can be utilized as a standardized atomic sample of known concentration for absolute concentration calibration purposes.

The development of flexibility in people of mature age through hatha yoga

Relevance: The level of flexibility development, along with other indicators, determines the level of human health. New approaches to the content of wellness classes for middle-aged and mature people have been developed and substantiated. Physical activity and physical exercises of a health-improving orientation are necessary throughout life. At the same time, each stage of age-related development is characterized by certain features of conducting activities and their orientation. For example, before the age of 35-40, when assimilation processes prevail in the body, classes should have a developmental orientation, and after 40 years - mainly preserving health.The aim of the study is to increase flexibility in women aged 30-45 years through hatha yoga classes.Organization and methods of research. The study involved women aged 35 to 45 years old who practiced yoga at the Lanfen studio in Yekaterinburg for 3 months. The generally accepted Indian method of teaching hatha yoga was used, which is characterized by performing a set of "asanas", which are canonized, typical yoga poses, with a delay in each pose from a few seconds to a minute or more with a slow transition from one pose to another. As a rule, the exercises were performed with low intensity using the principle of absolute concentration on the final result of their actions, as well as compliance with the rules of exercise (consistency and breathing).The results of the study and their discussion. The experimental data obtained in the course of the study allow us to assert that the model of the educational and training process aimed at developing the quality of flexibility, where special attention is paid to warm-up using intensive gymnastics and summing exercises, static-strength and corrective exercises, stretching and relaxation exercises, is really effective in relation to a young age and our climatic conditions. The main provisions of the work can be applied in the professional activities of specialists in the field of recreational physical culture and fitness, in physical culture and wellness work with other population, as well as for the development of flexibility among representatives of various sports.Conclusions. An experimental technique was developed to improve the quality of flexibility, and a pedagogical experiment was conducted for three months. The technique included joint warm-up, a dynamic complex "Surya Namaskar", 3 main complexes, and restorative asanas with pranayama to improve the quality of flexibility. The technique has shown its effectiveness. The overall flexibility indicators of the women tested increased, especially the mobility of the spine improved, since the spine is primarily rebuilt and stretched in this technique.

Neural network for evaluation of the impact of the UK COVID-19 national lockdown on atmospheric concentrations of PAHs and PBDEs

The impact of measures to restrict population mobility during the COVID-19 pandemic on atmospheric concentrations of polycyclic aromatic hydrocarbons (PAH) and brominated flame retardants (BFRs) is poorly understood. This study analyses the effects of meteorological parameters and mobility restrictions during the COVID-19 pandemic on concentrations of PAH and BFRs at the University of Birmingham in the UK utilising a neural network (self-organising maps, SOM). Air sampling was performed using Polyurethane Foam (PUF) disk passive samplers between October 2019 and January 2021. Data on concentrations of PAH and BFRs were analysed using SOM and Spearman's rank correlation. Data on meteorological parameters (air temperature, wind, and relative humidity) and mobility restrictions during the pandemic were included in the analysis. Decabromodiphenyl ether (BDE-209) was the most abundant polybrominated diphenyl ether (PBDE) (23–91% Σ7PBDEs) but was detected at lower absolute concentrations (4.2–35.0 pg m−3) than in previous investigations in Birmingham. Air samples were clustered in five groups based on SOM analysis and the effects of meteorology and pandemic-related restrictions on population mobility could be visualised. Concentrations of most PAH decreased during the early stages of the pandemic when mobility was most restricted. SOM analysis also helped to identify the important influence of wind speed on contaminant concentrations, contributing to reduce the concentration of all analysed pollutants. In contrast, concentrations of most PBDEs remained similar or increased during the first COVID-19 lockdown which was attributed to their primarily indoor sources that were either unaffected or increased during lockdown.

Gut Microbiome Links to Disease Stage and Immune Microenvironment in Patients with Chronic Lymphocytic Leukemia

Background Recent studies have shown extensive crosstalk between our immune system and the gut microbiome (GM). The host immune system plays a vital role in the maintenance of GM homeostasis by establishing a balance between eliminating invading pathogens and promoting the growth of beneficial microbes, whereas GM can modulate the immune system by cytokine production. As chronic lymphocytic leukemia (CLL) is characterized by a high rate of infectious complications and an altered immune microenvironment, it is warranted to uncover the link between microbiome composition and immune dysregulation in CLL patients. Thus, we investigated the microbiome pattern and potential connections to disease characteristics and phenotypes and distribution within the immune microenvironment in CLL patients requiring treatment. Methods Blood and feces samples were collected from 17 patients with CLL prior to targeted treatment with acalabrutinib or ibrutinib+venetoclax in clinical trials. T-cell maturation subsets, Treg/Th17 subsets, and activation- and exhaustion profiles were assessed in fresh blood samples by an 8-tube, 10 color flow cytometry panel (DuraClone), including one tube containing beads for calculating absolute concentrations. Fecal samples were subjected to shotgun sequencing using Illumina HiSeq and taxonomical profiling was done using an in-house bioinformatics pipeline. The bioinformatics analysis involved microbial species abundances comparison and co-occurrence identification across patient clusters. Electronic health records provided data on clinical baseline characteristics. Case report forms and data on use of antimicrobial drugs will be assessed at a later stage to investigate potential associations with infections or toxicity related adverse events. All patients provided written informed consent and the study was approved by the National Ethics Committee and the Data Protections Agency. Results Unsupervised clustering analyses based on GM composition data revealed two GM clusters, where we found an overlap constituting approximately 40% of the cohort between Binet stage C (7/10 patients) and GM cluster 2 (7/10 patients) (Figure 1A). GM cluster 2 was characterized by differentially abundant species such as Bacteroides fragilis and Eggerthela lenta, demonstrating the two highest fold change and elevated relative abundances (Figure 1B). Closer examination of the taxonomic composition characteristic for the 7 patients revealed a small set of indicator microbiome species, where Clostridium innocuum together with Clostridiales sp., Bacteroides fragilis and Escherichia coli, were the most significantly abundant co-occurring species for CLL patients with Binet C. Preliminary examination of T-cell subset data showed generally lower concentrations of T-cells in patients from GM cluster 2 compared to GM cluster 1, where the 7 patients overlapping with Binet C furthermore had decreased levels of Th17 CD4+ and Tc17 CD8+ cells compared to both the normal reference level and the rest of the cohort (Figure 1C). Conclusion Our preliminary results suggest a link between CLL stage at time of needing treatment, gut microbiome composition, represented by a subset of highly abundant bacterial species, and T-cell distribution with reduced Th17 and Tc17 subsets, to be further investigated. To our knowledge, we are thus among the first to present data connecting the gut microbiome to tumor microenvironmental changes in patients with CLL. Moving forward we will further explore microbiome-microenvironment interactions with focus on the production of short-chain fatty acids (bacterial metabolites which play crucial roles as immunomodulatory molecules) to investigate connections between microbiome, immune phenotypes, and clinical outcomes including infections, treatment-related toxicity, and disease progression, to light on novel avenues for therapeutic interventions in CLL.

Serum metallomics reveals insights into the associations of elements with the progression of preleukemic diseases toward acute leukemia.

Acute leukemia (AL) is a critical neoplasm of white blood cells with two main subtypes: acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). This study is focused on understanding the association of the preleukemic disease aplastic anemia (APA) with ALL and AML at metallomic level, using healthy subjects as a control. In this study, a validated and efficient inductively coupled plasma-mass spectrometry/MS-based workflow was employed to profile a total of 13 metallomic features. The study encompassed 41 patients with AML, 62 patients with ALL, 46 patients with APA, and 55 age-matched healthy controls. The metallomic features consisted of eight essential elements (Ca, Co, Cu, Fe, Mg, Mn, Se, and Zn) and five non-essential/toxic elements (Ag, Cd, Cr, Ni, and Pb). Six out of the 13 elements were found to be substantially different (P < .05) using absolute concentrations between serum samples of AL (ALL and AML) and preleukemia (APA) patients in comparison with healthy subjects. Elements including magnesium, calcium, iron, copper, and zinc were upregulated and only one element (chromium) was downregulated in serum samples of disease when compared with healthy subjects. Through the utilization of both univariate tests and multivariate classification modeling, it was determined that chromium exhibited a progressive behavior among the studied elements. Specifically, chromium displayed a sequential upregulation from healthy individuals to preleukemic disease (APA), and ultimately in patients diagnosed with ALL. Overall, metallomic-based biomarkers may have the utility to predict the association of APA with ALL.

Proton magnetic resonance spectroscopy-based evaluation of metabolic abnormalities in the right dorsolateral prefrontal cortex and caudate nucleus in treatment-naïve patients with obsessive-compulsive disorder.

Obsessive-compulsive disorder (OCD) is a common psychiatric disorder whose underlying pathophysiology is insufficiently understood. The pathophysiology of OCD may be related to abnormalities in the biochemistry of neurotransmitters. The aim of the present study was to measure the absolute concentration of various metabolites in the right dorsolateral prefrontal cortex (DLPFC) and caudate nucleus (CN) in treatment-naive patients with OCD and compare it with healthy controls (HCs). The present study investigated the metabolic profile of two brain regions, namely right DLPFC and CN, by using single voxel in-vivo proton magnetic resonance spectroscopy (1H MRS) in drug-naive patients with OCD (n = 17, mean age = 30.71 ± 10.104 years) and compared it with healthy controls (n = 13, mean age = 30.77 ± 5.449 years). The patients with OCD were recruited after appropriate psychometric assessments. The 1H-MRS experiments were performed using the 3 Tesla (3T) human MR scanner, and absolute concentrations of metabolites were estimated using the LC model. Significantly lower concentration of tNAA in the right DLPFC was observed in the patients with OCD compared to the controls, which may be indicative of neurodegeneration in this region. However, no significant differences were observed in the concentrations of the metabolites between the patients and controls in the CN region. The level of tNAA in DLPFC significantly correlated with the disability level (WHO-DAS) of the patients. The present study demonstrates abnormalities in the metabolic profile of an important region, DLPFC of the CSTC circuit, which is suggestive of neurodegeneration in the region in OCD patients.

53 Change in Cerebral Metabolite Concentrations Following Bariatric Surgery

Objective:Obesity is associated with adverse effects on brain health, including increased risk for neurodegenerative diseases. Changes in cerebral metabolism may underlie or precede structural and functional brain changes. While bariatric surgery is known to be effective in inducing weight loss and improving obesity-related medical comorbidities, few studies have examined whether it may be able to improve brain metabolism. In the present study, we examined change in cerebral metabolite concentrations in participants with obesity who underwent bariatric surgery.Participants and Methods:35 patients with obesity (BMI &gt; 35 kg/m2) were recruited from a bariatric surgery candidate nutrition class. They completed single voxel 1H-proton magnetic resonance spectroscopy at baseline (pre-surgery) and within one year post-surgery. Spectra were obtained from a large medial frontal brain region. Tissue-corrected absolute concentrations for metabolites including choline-containing compounds (Cho), myo-inositol (mI), N-acetylaspartate (NAA), creatine (Cr), and glutamate and glutamine (Glx) were determined using Osprey. Paired t-tests were used to examine within-subject change in metabolite concentrations, and correlations were used to relate these changes to other health-related outcomes, including weight loss and glycemic control.Results:Bariatric surgery was associated with a reduction in cerebral Cho (f[34j = -3.79, p &lt; 0.001, d = -0.64) and mI (f[34] = -2.81, p &lt; 0.01, d = -0.47) concentrations. There were no significant changes in NAA, Glx, or Cr concentrations. Reductions in Cho were associated with greater weight loss (r = 0.40, p &lt; 0.05), and reductions in mI were associated with greater reductions in HbA1c (r = 0.44, p &lt; 0.05).Conclusions:Participants who underwent bariatric surgery exhibited reductions in cerebral Cho and mI concentrations, which were associated with improvements in weight loss and glycemic control. Given that elevated levels of Cho and mI have been implicated in neuroinflammation, reduction in these metabolites after bariatric surgery may reflect amelioration of obesity-related neuroinflammatory processes. As such, our results provide evidence that bariatric surgery may improve brain health and metabolism in individuals with obesity.

79 The impact of inflammation on the absolute concentration of albumin and α1-acid glycoprotein in porcine skin

79 The impact of inflammation on the absolute concentration of albumin and α1-acid glycoprotein in porcine skin

Arctic Permafrost Thawing Enhances Sulfide Oxidation

AbstractPermafrost degradation is altering biogeochemical processes throughout the Arctic. Thaw‐induced changes in organic matter transformations and mineral weathering reactions are impacting fluxes of inorganic carbon (IC) and alkalinity (ALK) in Arctic rivers. However, the net impact of these changing fluxes on the concentration of carbon dioxide in the atmosphere (pCO2) is relatively unconstrained. Resolving this uncertainty is important as thaw‐driven changes in the fluxes of IC and ALK could produce feedbacks in the global carbon cycle. Enhanced production of sulfuric acid through sulfide oxidation is particularly poorly quantified despite its potential to remove ALK from the ocean‐atmosphere system and increase pCO2, producing a positive feedback leading to more warming and permafrost degradation. In this work, we quantified weathering in the Koyukuk River, a major tributary of the Yukon River draining discontinuous permafrost in central Alaska, based on water and sediment samples collected near the village of Huslia in summer 2018. Using measurements of major ion abundances and sulfate () sulfur (34S/32S) and oxygen (18O/16O) isotope ratios, we employed the MEANDIR inversion model to quantify the relative importance of a suite of weathering processes and their net impact on pCO2. Calculations found that approximately 80% of in mainstem samples derived from sulfide oxidation with the remainder from evaporite dissolution. Moreover, 34S/32S ratios, 13C/12C ratios of dissolved IC, and sulfur X‐ray absorption spectra of mainstem, secondary channel, and floodplain pore fluid and sediment samples revealed modest degrees of microbial sulfate reduction within the floodplain. Weathering fluxes of ALK and IC result in lower values of pCO2 over timescales shorter than carbonate compensation (∼104 yr) and, for mainstem samples, higher values of pCO2 over timescales longer than carbonate compensation but shorter than the residence time of marine (∼107 yr). Furthermore, the absolute concentrations of and Mg2+ in the Koyukuk River, as well as the ratios of and Mg2+ to other dissolved weathering products, have increased over the past 50 years. Through analogy to similar trends in the Yukon River, we interpret these changes as reflecting enhanced sulfide oxidation due to ongoing exposure of previously frozen sediment and changes in the contributions of shallow and deep flow paths to the active channel. Overall, these findings confirm that sulfide oxidation is a substantial outcome of permafrost degradation and that the sulfur cycle responds to permafrost thaw with a timescale‐dependent feedback on warming.

Plasma VEGF-D and sFLT-1 are potential biomarkers of hemodynamics and congestion in heart failure and following heart transplantation

BackgroundInflammation and tyrosine-kinases are known mediators in the pathobiology of cardiovascular disease. Plasma biomarkers reflecting these systems may provide a non-invasive complement reflecting haemodynamics, aiding in clinical decision-making. We therefore aimed to investigate the plasma levels of vascular and inflammatory proteins, and their associations with invasive haemodynamics in advanced heart failure (HF) before, and at multiple follow-ups after heart transplantation (HT). MethodsUsing multiplex sandwich immunoassays, absolute plasma concentrations of nine vascular and inflammatory proteins were assessed in 26 patients with advanced HF, before-HT, and at four-weeks, six-months, and one-year after-HT. Right heart catheterization (RHC) haemodynamics were assessed at the time of blood sampling. Repeated measures correlations were performed to evaluate the overall intra-individual development of plasma protein levels in relation to haemodynamics’ development over time. ResultsOut of nine proteins included initially, in advanced HF, elevated plasma levels of vascular endothelial growth factor D (VEGF-D) and soluble fms-like tyrosine kinase-1 (sFlt-1) decreased most markedly, at four-weeks (p<0.0001), and decreased further at six-months (p<0.05) and at the one-year follow-ups after-HT (p<0.05). Over time, plasma VEGF-D correlated strongest with haemodynamic parameters including pulmonary arterial wedge pressure (PAWP) (rmr= 0.75, 95% bootstrapped confidence interval (CI) 0.61-0.84, p<0.0001), followed by mean right atrial pressure (MRAP) (rmr= 0.74, 95% CI 0.61-0.82, p<0.0001), and mean pulmonary arterial pressure (mPAP) (rmr= 0.74, 95% CI 0.58-0.82, p<0.0001). Plasma sFlt-1 correlated also with multiple haemodynamic parameters including PAWP (rmr= 0.66, 95% CI 0.58-0.79, p<0.0001), MRAP (rmr= 0.64, 95% CI 0.58-0.81, p<0.0001), and mPAP (rmr= 0.61, 95% CI 0.51-0.76, p<0.0001). ConclusionsIn advanced HF, elevated plasma VEGF-D and sFlt-1 levels decrease early, already within four weeks after HT, and further throughout the first year postoperatively. Our findings support that high plasma VEGF-D and sFlt-1 concentrations before HT are related to congestion, and overall haemodynamic improvement. Plasma VEGF-D and sFlt-1 may consequently be potential non-invasive biomarkers for monitoring hemodynamic deterioration and congestion in HF, and surveillance after HT.

Determining How Gavaging Laying Hens with Lead (Pb) Affects Lead Concentration in Table Eggs, Bone, blood, and Liver

Previous research has demonstrated that lead (Pb2+, for the remainder of the paper referred to as Pb) and other heavy metals are present in table eggs from backyard birds. While the source of Pb exposure is unknown, exposure to the environment via the foraging behavior of backyard poultry is likely a significant factor. A longitudinal cohort study was conducted to better understand how oral Pb consumption correlates with Pb concentration in table eggs and other physiological compartments (i.e. bone, blood, and liver). In order of absolute mean concentration, Pb was most present in bone (226.24 ppb experimental vs. 31.00 ppb control), blood (14.47 ppb experimental vs 0.27 ppb control), liver (11.24 ppb experimental vs 0.75 ppb control), and egg (1.17 ppb experimental vs 0.06 ppb control). The low concentration of Pb in table eggs implies that Pb preferentially accumulates in other tissues aside from the egg. While this study showed that eggs have the lowest overall tropism for Pb, the presence of Pb in other tissues demonstrates a public health risk when chickens are orally exposed to Pb via oral consumption.

Copper retention influenced by an invasive and a native plant in riparian soil

Riparian soils are exposed to diverse anthropogenic stressors via aquatic pathways. Our study focuses on the impact of the invasive plant Impatiens glandulifera (Himalayan Balm) on processes that affect the filter and retention function of soils for copper, a regionally applied fungicide.Two soils, overgrown with the invasive I. glandulifera and by the native Urtica dioica were characterized for general soil properties and their copper retention ability assessed by a sequential extraction after seven days flooding with three different copper concentrations.We observed higher values for the absolute copper concentration in all fractions for the soil overgrown with I. glandulifera than for the soil overgrown with U. dioica. However, with respect to the total content, copper was more mobile in soil overgrown with U. dioica despite a higher organic matter content. The lower extraction recovery of the U. dioica soil suggests that more copper was mobilized in colloids which in long-term are easier washed out while I. glandulifera favors immobilization of organically chelated copper enhancing a legacy effect.Our results highlight the plant specific impact possibly induced by root exudates and plant residues affecting soil organic matter quality including the colloidal fraction and thus filter and retention functions of riparian soils.

Comparative seasonality of phytoplankton community in two contrasting temperate estuaries on the western coast of Korea

In estuaries, freshwater discharge functions as a regulator of physicochemical and biological properties. We assessed the seasonal variability of the phytoplankton community in response to hydrological features and nutrient dynamics in two contrasting estuaries in the presence and absence of a dam on the western coast of Korea. Diversity and evenness were also evaluated through chemotaxonomic analysis. Seasonal and inter-estuarine comparisons revealed the overall predominance of diatoms in all seasons and the differentiated composition of small phytoplankton populations in each estuary, which was mainly characterized by significant contribution of cryptophytes in the continuously flushed estuary in contrast to the seasonal occurrence of pelagophytes and cyanobacteria in the intermittently perturbed estuary. Our one-way analysis of similarity and similarity percentage analysis showed obvious inter-estuarine discrepancy of the phytoplankton community in winter in relation to the high dissolved inorganic nitrogen concentration in the natural estuary, implying that the impact of freshwater inflow on the phenological response of phytoplankton can be maximized during active seawater intrusion in dry seasons in the prevalence of freshwater and seawater in the estuary. The contribution swing of diatoms and cryptophytes during the study period reflects the seasonal variability in nutrient dynamics, including absolute concentrations and stoichiometric ratios, which is especially associated with P-limitation on the western coast of Korea. The occurrence of cyanobacteria with a summer peak of phytoplankton biomass in the dammed estuary during the study period indicates the role of an estuarine dam as a conduit transporting phytoplankton and dissolved inorganic nutrients. These findings further suggest that the phytoplankton community structure, differentiated by the presence and absence of dams, influences bottom-up regulation and thus the food web structure in estuaries.

The characteristics of rare earth elements in the main water filling sources of Sunan mining area

This study employs rare earth elements to investigate the features and procedures of water-rock interactions within aquifers of loose strata, sandstone, and limestone in the Sunan mining region of North Anhui, China. Through a comparison of the differential characteristics of rare earth elements across primary water sources, we are able to uncover the influence of water-rock interactions on the transfer and conversion of rare earth elements within various water-sediment systems. Indeed, the normalization of water compositions against host rock concentrations revealed a distinct pattern of rare-earth elements for each group of waters. Not only did the absolute concentrations of the elements in each sampling site change, but also the normalized patterns. In contrast to sediment samples, all water samples exhibit a clear enrichment of MREEs, but they also reveal a trend of HREEs enrichment. This is attributed to the differential adsorption effect of oxides on rare earth elements, which is influenced by pH, and the complexation reactions between rare earth elements and carbonate ions. The significant Ho and Ce anomalies in the water-sediment system are associated with robust water rock interactions, whereas the high Ba content significantly impacts the Eu anomaly. The enrichment of Eu is attributed to the interaction between the water environment and the dissolution of minerals rich in Eu. Furthermore, we utilize decision trees and recursive feature elimination techniques for selecting indices, and create a model that incorporates triangular fuzzy numbers (TFN), CRITIC, D-S evidence theory (DSET), factor space (FS), and set pair cloud model (SPCM) to differentiate, describe, and evaluate three distinct groups of waters with varying hydrofacies. The conclusion drawn is that sandstone and limestone aquifers are the main sources of water inrush, with a mixing ratio exceeding 50%. Moreover, this marks the inaugural attempt to utilize patterns of rare-earth elements for establishing a comparison between various water groups, thereby enabling us to distinguish and differentiate depletion patterns resulting from dilution processes from those resulting from precipitation processes, with the aim of determining the contribution rates of mine water. The findings offer valuable insights for predicting water disasters in the Sunan mining area.

Identification of a human blood biomarker of pharmacological 11β-hydroxysteroid dehydrogenase 1 inhibition.

11β-Hydroxysteroid dehydrogenase-1 (11β-HSD1) catalyses the oxoreduction of cortisone to cortisol, amplifying levels of active glucocorticoids. It is a pharmaceutical target in metabolic disease and cognitive impairments. 11β-HSD1 also converts some 7oxo-steroids to their 7β-hydroxy forms. A recent study in mice described the ratio of tauroursodeoxycholic acid (TUDCA)/tauro-7oxolithocholic acid (T7oxoLCA) as a biomarker for decreased 11β-HSD1 activity. The present study evaluates the equivalent bile acid ratio of glycoursodeoxycholic acid (GUDCA)/glyco-7oxolithocholic acid (G7oxoLCA) as a biomarker for pharmacological 11β-HSD1 inhibition in humans and compares it with the currently applied urinary (5α-tetrahydrocortisol + tetrahydrocortisol)/tetrahydrocortisone ((5αTHF + THF)/THE) ratio. Bile acid profiles were analysed by ultra-HPLC tandem-MS in blood samples from two independent, double-blind placebo-controlled clinical studies of the orally administered selective 11β-HSD1 inhibitor AZD4017. The blood GUDCA/G7oxoLCA ratio was compared with the urinary tetrahydro-glucocorticoid ratio for ability to detect 11β-HSD1 inhibition. No significant alterations were observed in bile acid profiles following 11β-HSD1 inhibition by AZD4017, except for an increase of the secondary bile acid G7oxoLCA. The enzyme product/substrate ratio GUDCA/G7oxoLCA was found to be more reliable to detect 11β-HSD1 inhibition than the absolute G7oxoLCA concentration in both cohorts. Comparison of the blood GUDCA/G7oxoLCA ratio with the urinary (5αTHF + THF)/THE ratio revealed that both successfully detect 11β-HSD1 inhibition. 11β-HSD1 inhibition does not cause major alterations in bile acid homeostasis. The GUDCA/G7oxoLCA ratio represents the first blood biomarker of pharmacological 11β-HSD1 inhibition and may replace or complement the urinary (5αTHF + THF)/THE ratio biomarker.