Specific Solid-phase Research Articles

A highly stable and leach resistant sodium copper titanate based ion-exchanger for immobilizing strontium: Comprehensive studies on preparation, characterization, adsorption and material stability

A leach resistant, stable strontium (Sr) specific solid phase ion exchange material that could be used as a matrix for immobilizing Sr-bearing nuclear waste was developed, and different studies were conducted to establish the material's stability. Sodium copper titanate (SCT) that was prepared by a simple solution synthesis method exhibited a high Sr removal tendency from pH 4 to 8, and is therefore capable of removing Sr from alkaline aqueous waste in the pH range. Sr adsorption was modeled using Langmuir, Freaundlich, Tempkin, and D-R isotherm models and the diffusion based reaction kinetics models have also been explored by modeling adsorption kinetics. Subsequent to Sr exchange to SCT at room temperature, the material was calcined at 673 K and 1273 K. Material stability of the Sr loaded SCT matrix was studied using thermogravimetric, SEM, X-ray diffraction and Raman spectrometric methods. Soxhlet leaching experiments were performed on the Sr-loaded SCT established the stability of the studied material under harsh conditions.

Microvolume analysis of 226Ra by inductively coupled plasma mass spectrometry: Environmental applications to high-resolution profile of wetland soil pore waters

BackgroundThe release to the environment of natural radionuclides like 226Ra due to human activities have raised concerns about human and ecosystem exposure. 226Ra’s resemblance to calcium and involvement in biological processes accentuate the importance of understanding its geochemical behavior and migration pathways. Soil and sediment pore waters provide valuable information but have proved to be challenging to analyze, requiring to push the limits of current sample preparation and detection methods often not scaled for low concentrated microvolumes of samples. A more efficient and accurate analytical method is therefore needed to get reliable data to support hydro-geochemical modeling. ResultsWe describe here a novel comprehensive approach for accurate 226Ra quantification in pore waters of a wetland located downstream of the former Rophin uranium mine. In order to highlight the migration of 226Ra between the different soil layers, microvolumes of soil pore waters were in situ sampled up to 50 cm depth employing Diffusive Equilibrium in Thin-Films (DET) probes. The workflow included spiking DET extracts with an in-house 228Ra tracer, specific solid-phase extraction with 50 mg of AnaLig Ra-01® resin, and elution fraction calcination. This process eliminated interferences and simplify the analysis matrix. Quantification relied on isotope dilution after measurement by ICP-MS hyphenated to a desolvator module and to a microsampler (150 µL injection). The resulting 1 cm-high-resolution profile revealed unusual 226Ra enrichment with depth, signs of Ra mobility from the solid contamination source. These elements are essential for assessing 226Ra distribution coefficients across soil horizons and subsequent wetland remobilization considerations. Significance and noveltyThis first methodological advance for 226Ra constitutes a significant step to understand 226Ra behavior i.e., to quantify its activity level, fluxes inside of wetland soils or at the interface overlying waters/sediments. Its potential extension to studies involving other elements underscores its broader applicability in environmental research. The findings contribute to evidence-based decision-making for environmental protection and management, aiding in the preservation of ecological integrity and human health.

The comparison of skin prick test, serological specific IgE test and solid phase immunoassay in the diagnosis of infantile allergic diseases.

This retrospective study was designed in order to compare the usefulness of skin prick tests, serological specific IgE tests and solid phase immunoassays in the diagnosis of infantile allergic diseases. Two hundred infants with allergic diseases (120 infants with eczema and 80 infants with asthma), diagnosed in the Pediatric Clinic of our hospital between June of 2011 and June of 2016, were selected to participate in the study. 100 healthy infants were included in a control group. All infants received a skin prick test, a serological specific IgE test or a solid phase immunoassay. A total of 38 allergens were used for the infants receiving skin prick test. The IgE in the serum samples of infants was detected by immunoblotting. And, allergens were detected by solid phase immunoassay in the infants receiving solid phase immunoassay. The positive predictive value, negative predictive value, specificity and sensitivity for these 3 diagnostic methods were analyzed after generating a ROC curve. In the eczema group, the AUCs (the area under the ROC curve) for skin prick test, serological specific IgE test and solid phase immunoassay were 0.8685±0.0187, 0.8137±0.024 and 0.9682±0.0358, respectively. The sensitivities for skin prick test, serological specific IgE test and solid phase immunoassay were 85.70%, 83.62% and 88.72%, respectively. And, the specificities were 74%, 68% and 83%, respectively. The positive predictive values were 87.27%, 92.37% and 90.00%; and the negative predictive values were 57.04%, 51.11% and 78.15%, respectively. In the asthma group, the AUCs for skin prick test, serological specific IgE test and solid phase immunoassay were 0.8186±0.0161, 0.8037±0.0241 and 0.952±0.0421, respectively. The sensitivities for skin prick test, serological specific IgE test and solid phase immunoassay were 84.70%, 88.62% and 96.72%, respectively. The specificities were 76%, 64% and 81%, respectively; the positive predictive values were 81.34%, 85.59% and 84.54%, respectively. The negative predictive values were 69.29%, 67.14% and 70.08%, respectively. While all three methods were effective in the diagnosis of infantile allergic diseases, the solid phase immunoassay was superior to the other two methods, as evidenced by the obtained values and we recommend it for clinical application as a goal standard.

Biological age markers in solid-phase structures of the oral fluid

Markers of aging known today do not clearly define the biological age of the organism, which creates the need for their further search. The oral fluid is a convenient object for such studies, since it contains proteins whose conformation corresponds to the age of the organism. The method developed by the authors allows, by transferring biological fluids into a solid phase, to transform the structure of the molecular-level components dissolved in them to a level accessible to visual analysis.
 The aim of the study is to search for markers of biological age in the solid-phase structures of the oral fluid.
 Materials and methods. The structures of the solid phase oral fluid of 240 people with a sanitized oral cavity were studied. There are four age groups of 60 patients each: middle age; elderly; senile and long-livers. Oral fluid was taken in the morning on an empty stomach. The method of cuneiform dehydration of biological fluids was used. Dehydration of drops of oral fluid was carried out on special test cards under standard conditions. As a result, dry films (facies) were obtained, the structural features of which were examined by microscopy.
 Results. The structure of oral fluid facies is determined by the ratio of salt and organic substances present in it. During the formation of a facies, salts bind to proteins that have an abnormal conformation. In middle-aged patients, the facies have a clear division into saline and marginal (protein) zones. With age (elderly and senile age), due to the increased activity of catabolic processes, in the facies of the oral fluid, an increasing area is occupied by organic substances, and the areas occupied by salts decrease, while the facies lose their physiological structuring. At the same time, the facies of the oral fluid of most long-livers retain a structure similar to the facies of middle-aged representatives.
 Conclusions. The biological age of the organism is determined by the level of its autointoxication by proteins with pathological conformation. Autotoxins are contained in the oral fluid and are manifested in the structure of its facies. Due to natural age-related metabolic shifts towards an increase in catabolic processes, the protective systems that block autointoxication by metabolites cease to provide their complete neutralization, which is reflected in the facies structure. Facies of the oral fluid of long-livers have a fundamentally different structure compared with the facies of the elderly and senile persons, indicating a low degree of autointoxication of the organism of long-livers, which determines a longer life span. Thus, specific solid phase structures of oral fluid facies can be used as objective markers of biological age.

Specific recognition and solid phase extraction of three primary aromatic amines based on molecularly imprinted polymer monolith for the migration detection in food contact materials

A molecularly imprinted polymer (MIP) monolith was in situ synthesized in pipette tip with 4,4′-methylenedianiline (4,4′-MDA) as template molecule and 4-vinylpyridine as functional monomer. The 4,4′-MDA-MIP monolith was used to extract three primary aromatic amines (PAAs), including 4,4′-MAD, 4-aminobiphenyl and 3,3′-dichlorobenzidine. The 4,4′-MDA-MIP monolith have specific recognition capacity and high adsorption capacity for the three PAAs. The imprinting factor for 4,4′-MAD was up to 4.26 and the adsorption capacity for 4-aminobiphenyl was up to 117.94 mg g−1. The extraction parameters for the pipette tip solid-phase extraction (PTSPE) were optimized. A determination method for the three PAAs was established by coupling the PTSPE with high performance liquid chromatography-diode array detector. The detection linear range (LRs) was 0.70–500 µg kg−1 (R2 > 0.998), and the limits of detection (LODs) was 0.23–1.00 µg kg−1 (S/N = 3). The method was used for the migration detection of the PAAs from four polypropylene spoons, which showed satisfactory recovery of 87.4–110.6 %, indicating that the 4,4′-MDA-MIP monolith had good enrichment ability for PAAs in a complex matrix.

Highlighting Recent Crystalline Engineering Aspects of Luminescent Coordination Polymers Based on F-Elements and Ditopic Aliphatic Ligands.

Three principal factors may influence the final structure of coordination polymers (CPs): (i) the nature of the ligand, (ii) the type and coordination number of the metal center, and (iii) the reaction conditions. Further, flexible carboxylate aliphatic ligands have been widely employed as building blocks for designing and synthesizing CPs, resulting in a diverse array of materials with exciting architectures, porosities, dimensionalities, and topologies as well as an increasing number of properties and applications. These ligands show different structural features, such as torsion angles, carbon backbone number, and coordination modes, which affect the desired products and so enable the generation of polymorphs or crystalline phases. Additionally, due to their large coordination numbers, using 4f and 5f metals as coordination centers combined with aliphatic ligands increases the possibility of obtaining different crystal phases. Additionally, by varying the synthetic conditions, we may control the production of a specific solid phase by understanding the thermodynamic and kinetic factors that influence the self-assembly process. This revision highlights the relationship between the structural variety of CPs based on flexible carboxylate aliphatic ligands and f-elements (lanthanide and actinides) and their outstanding luminescent properties such as solid-state emissions, sensing, and photocatalysis. In this sense, we present a structural analysis of the CPs reported with the oxalate ligand, as the one rigid ligand of the family, and other flexible dicarboxylate linkers with –CH2– spacers. Additionally, the nature of the luminescence properties of the 4f or 5f-CPs is analyzed, and finally, we present a novel set of CPs using a glutarate-derived ligand and samarium, with the formula [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2]•(2,2′-bipy) (α-Sm) and [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2] (β-Sm).

Autoantibodies against ACE2 and angiotensin type-1 receptors increase severity of COVID-19

The renin-angiotensin system (RAS) plays a major role in COVID-19. Severity of several inflammation-related diseases has been associated with autoantibodies against RAS, particularly agonistic autoantibodies for angiotensin type-1 receptors (AA-AT1) and autoantibodies against ACE2 (AA-ACE2). Disease severity of COVID-19 patients was defined as mild, moderate or severe following the WHO Clinical Progression Scale and determined at medical discharge. Serum AA-AT1 and AA-ACE2 were measured in COVID-19 patients (n = 119) and non-infected controls (n = 23) using specific solid-phase, sandwich enzyme-linked immunosorbent assays. Serum LIGHT (TNFSF14; tumor necrosis factor ligand superfamily member 14) levels were measured with the corresponding assay kit. At diagnosis, AA-AT1 and AA-ACE2 levels were significantly higher in the COVID-19 group relative to controls, and we observed significant association between disease outcome and serum AA-AT1 and AA-ACE2 levels. Mild disease patients had significantly lower levels of AA-AT1 (p < 0.01) and AA-ACE2 (p < 0.001) than moderate and severe patients. No significant differences were detected between males and females. The increase in autoantibodies was not related to comorbidities potentially affecting COVID-19 severity. There was significant positive correlation between serum levels of AA-AT1 and LIGHT (TNFSF14; rPearson = 0.70, p < 0.001). Both AA-AT1 (by agonistic stimulation of AT1 receptors) and AA-ACE2 (by reducing conversion of Angiotensin II into Angiotensin 1-7) may lead to increase in AT1 receptor activity, enhance proinflammatory responses and severity of COVID-19 outcome. Patients with high levels of autoantibodies require more cautious control after diagnosis. Additionally, the results encourage further studies on the possible protective treatment with AT1 receptor blockers in COVID-19.

Guanidyl-functionalized polyhedral oligomeric silsesquioxane porous hybrid polymer coating for specific solid phase microextraction of phthalate esters in foodstuff

A guanidyl-functionalized polyhedral oligomeric silsesquioxane (G-POSS) porous polymeric hybrid coating was developed for specific solid-phase microextraction (SPME) of phthalate esters (PAEs), via in-situ click photopolymerization on a thiolated stainless steel (SS) fiber. The guanidyl-functionalized l-cysteine (G-Cys) monomer was fast copolymerized with methacryl substituted polyhedral oligomeric silsesquioxane in the presence of initiator and porogen. The resultant G-POSS hybrid coating exhibited large specific surface, fast mass transfer, and good stability (water- and thermal-resistance). It showed mixed-mode recognition regime (hydrogen bonding, hydrophobic interaction and “molecular sieve effect”), and therefore demonstrated great benefits in SPME - gas chromatography-mass spectrometry (GC–MS) analysis of PAEs with low detection limits (0.054–2.51 ng L−1), wide linear range (1.0–3000.0 ng L−1), and appropriate repeatability. The coating was successfully applied for the enrichment and analysis of PAEs in milk and rice samples. This work indicates that the POSS-based functionalized porous hybrid polymer is a promising candidate for the enrichment of complicated samples.

Are Molecularly Imprinted Polymers (MIPs) Beneficial in Detection and Determination of Mycotoxins in Cereal Samples

The process of matrix clean-up and extraction of analytes has a significant influence on the detection and determination of the analyte, especially in trace amounts. Molecularly imprinted polymers (MIPs) are solid particles that can absorb specific molecules regarding the template molecule used in the synthesis process of each type of MIP. As a result, they can be used in more effective and more specific solid-phase extraction processes. On the other hand, mycotoxins are second metabolites of molds and fungus which are potentially cytotoxic and/or genotoxic even in trace amounts, and due to extensive consumption of cereals and the great concern of public health, several methods were developed and currently are in the process of development to detect and determine the presence and amounts of mycotoxins in cereals. This review is aimed to investigate the application and efficacy of MIPs in detecting and determination of mycotoxins in cereals.

Екстракція ксенобіотиків групи ПАВ з насіння соняшнику

That paper is results of obtaining method for oil extract that concentrates lipophilic xenobiotics from oils seeds and can be used to prepare samples of sunflower seeds for measuring the concentration of polycyclic aromatic hydrocarbon. In this work olive raw materials was grinded and homogenizated. The grinding time of each sample was individual and was varied from 0.5 to 8 minutes. The optimum conditions for homogenization of samples and conditions for xenobiotics extraction by means of maceration method are determined, optimal conditions are proposed for carrying out the procedure for preparing samples of sunflower seeds for the study of surfactant content. The investigated method of preparation of samples consists in obtaining an oil extract from a chloroform extract which was obtained by maceration, intensified by constant stirring at a rate of 200 revolutions per minute during 3 hours at a chloroform ratio:raw material equal to 1:10. Pieces are shredded to size of ≤ 2,0 mm of sunflower seeds used for extraction. Each sample of sunflower seeds and samples of sunflower seeds, after artificial contamination with solutions of polycyclic aromatic hydrocarbons group xenobiotics analytical standards (PAHs: benzo(a)anthracene, chrysene, benzo(a)pyrene, benzo(b)fluoranthenum) were investigated. The quantitative and qualitative composition of the oil extracts obtained from the lipophilic xenobiotics of the polycyclic aromatic hydrocarbons group was investigated by the method of highperformance liquid chromatography with ultraviolet detector (HPLC/FLD) developed for surfactant laboratory control in vegetable oils at the NULES of Ukraine structural depatrment. The chromatographic control of xenobiotics of oil extraction comprises a step of specific solid-phase extraction of polycyclic aromatic hydrocarbons. During the study of vegetable oils, it was discovered that on the column for solid-phase extraction there is an accumulation of chemical compounds that in the chemical structure belong to the class of aromatic compounds. It has been established that all compounds of the polycyclic group tested in the sample are removed during the maceration process. For laboratory tests of sunflower seeds artificially enriched with surfactants, it is characteristic that the established concentration is greater than the concentration of xenobiotics, the percentage of xenobiotic extraction is greater than 100%. This is due to the fact that a sample of sunflower seeds had a certain level of contamination, the quantitative measurement of trace amounts of components of a mixture of xenobiotics is limited to the limit of the quantitative measurement and technical capabilities of the HPLC/FLD equipment. The addition of analytical standards for surfactant mixtures can reveal the content of total contamination within the maximum error of the method (up to 20%). This method of preparing samples of sunflower seeds can also be offered for the preparation of samples of samples of other oil-containing raw materials, such as flax seeds. In the oil extracts of samples of sunflower seeds, which were not artificially enriched with surfactants, a list of normalized xenobiotics of the group of polycyclic aromatic hydrocarbons was found.

The comparison of skin prick test, serological specific IgE test and solid phase immunoassay in the diagnosis of infantile allergic diseases.

This retrospective study was designed in order to compare the usefulness of skin prick tests, serological specific IgE tests and solid phase immunoassays in the diagnosis of infantile allergic diseases. Two hundred infants with allergic diseases (120 infants with eczema and 80 infants with asthma), diagnosed in the Pediatric Clinic of our hospital between June of 2011 and June of 2016, were selected to participate in the study. 100 healthy infants were included in a control group. All infants received a skin prick test, a serological specific IgE test or a solid phase immunoassay. A total of 38 allergens were used for the infants receiving skin prick test. The IgE in the serum samples of infants was detected by immunoblotting. And, allergens were detected by solid phase immunoassay in the infants receiving solid phase immunoassay. The positive predictive value, negative predictive value, specificity and sensitivity for these 3 diagnostic methods were analyzed after generating a ROC curve. In the eczema group, the AUCs (the area under the ROC curve) for skin prick test, serological specific IgE test and solid phase immunoassay were 0.8685 ± 0.0187, 0.8137 ± 0.024 and 0.9682 ± 0.0358, respectively. The sensitivities for skin prick test, serological specific IgE test and solid phase immunoassay were 85.70%, 83.62% and 88.72%, respectively. And, the specificities were 74%, 68% and 83%, respectively. The positive predictive values were 87.27%, 92.37% and 90.00%,; and the negative predictive values were 57.04%, 51.11% and 78.15%, respectively. In the asthma group, the AUCs for skin prick test, serological specific IgE test and solid phase immunoassay were 0.8186 ± 0.0161, 0.8037 ± 0.0241 and 0.952 ± 0.0421, respectively. The sensitivities for skin prick test, serological specific IgE test and solid phase immunoassay were 84.70%, 88.62% and 96.72%, respectively. The specificities were 76%, 64% and 81%, respectively; the positive predictive values were 81.34%, 85.59% and 84.54%, respectively. The negative predictive values were 69.29%, 67.14% and 70.08%, respectively. While all three methods were effective in the diagnosis of infantile allergic diseases, the solid phase immunoassay was superior to the other two methods, as evidenced by the obtained values and we recommend it for clinical application as a goal standard.

A sensitive and specific solid-phase extraction-gas chromatography-tandem mass spectrometry method for the determination of 11 haloacetic acids in aqueous samples.

A method for the analysis of 11 haloacetic acids in water samples has been developed. It involves enrichment of the target analytes from water samples by solid-phase extraction, derivatization to methyl esters, and gas chromatography coupled with tandem mass spectrometry determination. Gas chromatography conditions were optimized for a good separation of all haloacetic acids in a short runtime. Data were acquired in the multiple reaction monitoring mode. Six solid-phase extraction sorbents among the most widely used in environmental analysis were tested. Bakerbond SDB was retained because it has been shown to provide the best results for a large class of targeted haloacetic acids. The performances of the developed method have been assessed according to the French Standard NF T 90-210. The calibration curves for all the studied haloacetic acids had consistent slopes with r2 values > 0.99. Quantification limits between 0.01 and 0.50 µg l-1 were achieved. Satisfactory repeatability (relative standard deviation ≤ 14.3%) and intermediate precision (relative standard deviation ≤ 15.7%) were obtained. Applied to the analysis of 15 untreated water samples collected from three rivers, the method allowed the detection of five haloacetic acids including monochloroacetic acid (in 100% of the samples, <0.5-1.85 µg l-1), dichloroacetic acid (87%, <0.05-0.22 µg l-1), trichloroacetic acid (93%, <0.05-0.52 µg l-1), dibromoacetic acid (53%, <0.01-0.40 µg l-1), tribromoacetic acid (20%, <0.05-0.14 µg l-1), and bromodichloroacetic acid (6%, < 0.05 µg l-1).

Plasma surfactant protein-A levels in apparently healthy smokers, stable and exacerbation COPD patients.

Objective:To compare the plasma level of surfactant protein-A in apparently healthy smokers, stable and exacerbation Chronic Obstructive Pulmonary Disease (COPD) patients.Methods:This was a comparative study conducted from January, 2015 to March, 2016. This study was conducted on 87 subjects of both gender and age between 30-70 years. Of the total 87 subjects; 29 subjects were “healthy smokers” selected from general population as control group. Another 29 were “stable COPD” patients free of exacerbation since last six weeks. Lastly, another 29 subjects were “exacerbated COPD” patients with 7-10 days of exacerbation. COPD was diagnosed on the basis of relevant history and spirometry showing post bronchodilator FEV1/FVC <0.70. Surfactant Protein-A level (ng/ml) was estimated by a specific solid phase enzyme linked immunosorbent assay (ELISA) using automated EIA analyzer.Results:The SP-A levels, determined by competitive ELISA, was significantly higher (P<0.025) in healthy smokers (44.19±39.17 ng/ml) and exacerbated (43.86±40.17) than the stable COPD (25.89±18.85) patients. The lung function parameters (FEV1, FVC and FEV1/ FVC) were lower in COPD patients compared to healthy smokers and were related to the duration of smoking.Conclusion:Current smokers and exacerbated patients had higher values of SP-A protein than stable COPD patients since they had stopped smoking.

Primary and Sub-Primary Particle Level Lithium Ion Battery Diagnostics Using Chemical-Sensitive STEM Tomography, Aberration-Corrected Imaging and Eels

The results of using newly developed chemical-sensitive scanning transmission electron microscopic (STEM) tomography, aberration-corrected imaging, and STEM-EELS to study structural changes of electrode materials for Li-ion battery will be reported. Some initial results regarding the structural irreversibility and chemical segregation of layer-layer compounds relating to their composition will be discussed as an example. Our results show that upon charge/discharge cycles, it is possible to use STEM tomography to three-dimensionally resolve the internal pore structure and its development with sub-nanometer resolution. This structural degradation is correlated with chemical segregation of the electrode materials at two drastically different length scale—single-digit nanometer and sub-micron length scales. Using our experimental results as a direct input for our high-throughput ab initio calculations, we are able to show that the solubility of transition metals in a specific solid phase can be used as an important parameter in predicting the structural reversibility of transition metal cathode materials. Acknowledgements This work was supported by the U.S. Department of Energy, the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies (BMR and VTO Battery500 projects) under Contract Number DE-AC02-98CH10886 This research used resources of the Center for Functional Nanomaterials, which is a U.S. DOE Office of Science Facility, at Brookhaven National Laboratory under Contract No. DE-SC0012704

A novel DNA/histone H4 peptide complex detects autoantibodies in systemic lupus erythematosus sera.

BackgroundThe detection of anti-dsDNA antibodies is critical for the diagnosis and follow-up of systemic lupus erythematosus (SLE) patients. The presently available assays are characterized by a non-optimal specificity (solid phase assays) or sensitivity (Crithidia Luciliae immunofluorescence test (CLIFT)). To overcome the limits of CLIFT and solid phase chromatin assays, we explored the diagnostic potential of an assay based on plasmid DNA containing a highly bent fragment of 211 bp from Crithidia Luciliae minicircles, complexed with histone peptides.MethodsElectrically neutral complexes of PK201/CAT plasmid (PK) DNA and histone 4 (H4) peptides were evaluated by electromobility shift assay. Complexes of H4 peptides and PK were absorbed to the solid phase to detect specific immunoglobulin G (IgG) in sera. Sera from 109 SLE patients, 100 normal healthy subjects, and 169 disease controls were tested.ResultsH4(14-34) containing the consensus sequence for DNA binding interacts with PK, retarding its migration. H4(14-34)/PK complexes were used to test sera by ELISA. Anti-H4-PK antibodies were detected in 56 % of SLE sera (more frequently in patients with skin or joint involvement) versus 5.9 % in disease controls; inhibition assays show that sera react with epitopes present on DNA or on the complex, not on the peptide. Antibody titer is correlated with European Consensus Lupus Activity Measurement (ECLAM) score and anti-complement component 1q (C1q) antibodies, negatively with C3 levels. Anti-H4-PK antibodies compared with CLIFT and solid phase dsDNA assays display moderate concordance.ConclusionsThe H4/PK assay is a simple and reliable test which is useful for the differential diagnosis and evaluation of disease activity in SLE patients.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-016-1117-8) contains supplementary material, which is available to authorized users.

Biogeochemistry of Ni and Pb in a periodically flooded arable soil: Fractionation and redox-induced (im)mobilization

The redox-induced (im)mobilization of nickel (Ni) and lead (Pb) under pre-definite redox conditions and their binding forms were studied in a periodically flooded, slightly acidic arable soil enriched with serpentine minerals at the Velika Morava River valley, Serbia. The total contents of Ni and Pb were 152 and 109 mg kg−1, respectively. Geochemical fractionation of Ni, combined with mineralogical analysis, confirmed its geogenic origin in the soil. Potentially mobile fractions were the dominating binding forms of Pb; thus, indicating anthropogenic sources as prevailing. Risk assessment indicated a low risk of Ni and Pb transfer from soil to other environmental constituents. However, the results imply that geogenic metals might pose higher environmental risk than those from anthropogenic origin, in dependence of their total concentrations and contents in the specific solid-phase fractions. Flooding of the soil was simulated in an automated biogeochemical microcosm system, which allows a control and a continuous measurements of redox potential (EH) and pH. Subsequently, the EH was increased in steps of approximately 100 mV from anoxic to oxic conditions. Concurrently, the concentrations of soluble Ni, Pb, iron (Fe), manganese (Mn), dissolved organic carbon (DOC), and sulfates were measured. The EH was brought from low to high values (−220 to 520 mV) and correlated negative with soluble Ni, Pb, Fe, Mn and DOC. Soluble Ni ranged from 125 to 228 μg l−1 while Pb ranged from 3.0 to 21.4 μg l−1. Concentrations of both metals in solution were high at low EH and decreased with increasing EH. Nickel immobilization may be attributed to sorption to or co-precipitation with re-oxidized Fe-Mn (hydr)oxides, whereas Pb, in addition, might be immobilized via precipitation with inorganic ligands, such as carbonates and phosphates. The results imply that Ni and Pb solubility might also be related to the formation of metal-DOC complexes. The detected dynamic and mechanisms might be useful in providing critical information for assessing the potential environmental risk and creating appropriate environmental management strategies for agricultural areas enriched with Ni and Pb.

Detection of 1,N(2)-propano-2'-deoxyguanosine in human urine by stable isotope dilution UHPLC-MS/MS analysis.

A sensitive and accurate stable isotope dilution UHPLC-MS/MS method was developed and validated for the detection and quantification of ProdG adducts in human urine, a surrogate for the ProdG adducts in genomic DNA of human. A specific solid phase extraction (SPE) approach was established for selective enrichment of urinary ProdG adducts and elimination of urinary matrix facilitating the coupled MS/MS detection. The recovery of the method is estimated about 84.8-107.2%, and the precision are about 0.8-3.6% for intraday and 2.8-10.0% for interday. Due to that the matrix effect is efficiently eliminated by SPE pretreatment, the limits of detection (LODs, S/N=3) and quantification (LOQs, S/N=10) are decreased to 100 and 300 amol for urinary ProdG adducts, respectively. By coupling the developed SPE pretreatment with the UHPLC-MS/MS analysis, ProdG adducts were accurately quantified in healthy human urine.

Effect of Cattle Grazing Routine on Erosion Processes, Harvest Yield and Quality of Fodder in Subalpine Belt of North Ossetia

Background/Objectives: The research is aimed at studying the effect of the pastureland use routine on altering the indicators of the soil fertility and on the erosion process development. Methods/Statistical Analysis: The studies were conducted in the mountains at an altitude of 1570 m above sea level on the mountain meadow subalpine soils with acidic reaction of soil solution (рН=5,9). The chemical analyses of the average runoff sample and that of the washout sample were carried out to determine the contents of the accessible forms of such nourishing elements as nitrogen, phosphorus and potassium. Findings: This study shows that in the middle of the last century a significant amount of agricultural products were produced in the North Caucasus Mountains; this output was significantly reduced due to soil erosion caused by poorly plant-protected surface and livestock congestion. Erosion leads to dispersion of soil horizon structure, megastructure reduction and increase in dust, it also results in increased soil specific weight and solid phase unit weight, in decreased air and capillary porosity with reduction of aggregate water stability and water permeability. In the absence of grazing, the total losses of nitrogen, phosphorus and potassium amounted to 7.84 kg/ha and 296.56 kg/ha with intensive pasturing, which was higher by 37.8 times. With the admissible levels of grazing intensity no reliable data for the productivity alteration was obtained, and in the grazing routine modes of 2/15, 3/10, 3/15 a decrease in the productivity was established. Grazing lowers the grass stand quality, while increasing the proportion of fiber, fat and ash. The yield of nutritional chemicals per 1 hectare increased under optimal grazing conditions and decreased under intensive grazing routines. Applications/Improvements: Recommendations for cattle grazing routines have been developed with regard to degraded and normally functioning pasturelands. It is proposed to avoid excessive grazing routines

Chronic antibody-mediated rejection: new diagnostic tools - clinical significance of C4d deposition and improved detection and characterization of human leucocyte antigen antibodies.

Despite improvements in outcomes of solid organ transplantation (SOT), chronic deterioration of allografts remains an important problem and is associated with increased morbidity and mortality 1. With the implementation of sensitive and specific solid phase immunoassays (SPI) for identification of donor-specific anti-human leucocyte antigen (HLA) antibodies (DSA), and with the improved understanding of the pathogenic effect of alloantibodies, it is well accepted that chronic graft loss is part of the antibody-mediated rejection (AMR) spectrum 1,2. Circulating DSAs, either present prior to transplant or developed de novo, may bind to graft endothelial cells, promoting the classical pathway of complement activation, and the inactive product C4d bound covalently to tissue, provides the ‘footprint’ of antibody-mediated allograft damage 3. Correlation between the level of DSA in the serum, C4d positivity in the biopsy and severity of microvascular damage has been shown by several investigators 4,5. However, C4d-negative biopsies with circulating DSA also showed microcirculation damage and increased expression of endothelial genes 6. A recent publication summarizes the revised Banff criteria for AMR in renal and non-renal allografts, including C4d-negative AMR 7. DSAs have been shown to promote various types of AMR, from the acute to the chronic form of rejection also termed as transplant glomerulopathy in renal, cardiac allograft vasculopathy in heart and bronchiolitis obliterans in lung transplants. Although the HLA antibodies may appear before loss of function and are highly predictive of poor outcome, there is still controversy concerning: (i) whether antibodies detected solely by highly sensitive techniques are clinically relevant, (ii) how often to monitor post-transplant and (iii) when to implement antibody removal therapies in the absence of clinical dysfunction.

Selective extraction of dimethoate from cucumber samples by use of molecularly imprinted microspheres

Molecularly imprinted polymers for dimethoate recognition were synthesized by the precipitation polymerization technique using methyl methacrylate (MMA) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker. The morphology, adsorption and recognition properties were investigated by scanning electron microscopy (SEM), static adsorption test, and competitive adsorption test. To obtain the best selectivity and binding performance, the synthesis and adsorption conditions of MIPs were optimized through single factor experiments. Under the optimized conditions, the resultant polymers exhibited uniform size, satisfactory binding capacity and significant selectivity. Furthermore, the imprinted polymers were successfully applied as a specific solid-phase extractants combined with high performance liquid chromatography (HPLC) for determination of dimethoate residues in the cucumber samples. The average recoveries of three spiked samples ranged from 78.5% to 87.9% with the relative standard deviations (RSDs) less than 4.4% and the limit of detection (LOD) obtained for dimethoate as low as 2.3μg/mL.