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Around 1.5% of the total clinical biochemistry tests performed in laboratories are affected by preanalytical errors. Large, automated chemistry analysers prevent errors and interference by using control systems such as spectrophotometric measurements to evaluate serum indices, i.e. haemolysis (H), icterus (I), and lipemia/turbidity (L). However, still preanalytical errors can remain undetected. Our laboratory experienced an incident caused by laboratory-induced preanalytical errors, where approximately 100 sedimented lithium heparin samples bypassed centrifugation and entered our automated analyser. Based on index results, we investigated the possibility of using turbidimetry measurement, as a mean to prevent analysis on uncentrifuged sedimented whole blood. 14078 L-indices from 8 days in August 2019 were extracted from the middleware and used to develop and evaluate stop rules. Similarly, a one-day validation dataset was identified in December 2020 and used for an independent validation. Three different types of stop rules were evaluated: (1) A single L-index result above a cut-off; (2) A sequence of an L-index results above a cut-off; (3) A simple moving average of n results above a cut-off. A stop rule using 3 consecutive L-indices of 40–60 was found to be superior. However, practical implementation in the instrument middleware on a Roche Cobas 8000 only allowed a simple moving average of 110 (n = 5). This rule was found to be able to identify and stop sedimented whole blood analysis. Additionally, the rule has minimal impact on daily routine production in the laboratory. [ABSTRACT FROM AUTHOR]

Regular and irregular molecular brushes with polydimethylsiloxane backbone and poly-2-isopropyl-2-oxazoline side chains have been synthesized. Prepared samples differed strongly in the side chain grafting density, namely, in the ratio of the lengths of spacer between the grafting points and the side chains. The hydrodynamic properties and molecular conformation of the synthesized grafted copolymers and their behavior in aqueous solutions on heating were studied by the methods of molecular hydrodynamics and optics. It was found that the regularity and the grafting density do not affect the molecular shape of the studied samples of molecular brushes in the selective solvent. On the contrary, the grafting density is one of the most important factors determining the thermoresponsivity of grafted copolymers. It was shown that in analyzing self-organization and LCST values in aqueous solutions of poly-2-isopropyl-2-oxazolines with complex architecture, many factors should be considered. First is the molar fraction of the hydrophobic fragment and the intramolecular density. It was found that molar mass is not a factor that greatly affects the phase transition temperature of poly-2-isopropyl-2-oxazolines solutions at a passage from one molecular architecture to another.

The paper presents the results of in situ studies of marine particles of different nature using a submersible digital holographic camera (DHC) during the Arctic expedition. It also describes the features, performance specifications, and possibilities of the DHC and the DHC technology. The DHC technology can be used for noninvasive automatic evaluation of spatial and temporal characteristics of plankton, including the distribution of plankton concentrations. The comparison of quantitative analysis of zooplankton net samples and classification results using the DHC revealed that the error of the DHC classification of mesoplankton at the level of the main systematic orders was about 30%. The results of determining the data on the medium, such as water turbidity, according to the radiation shielding factor (degree) by the particles of the Suspension taxon using the DHC technology are presented; the prospects for studying the size of gas bubbles and their volume content according to the Bubble taxon data are shown. The use of holographic data for in situ point estimates is considered.

Background: Mechanisms by which chronic kidney disease (CKD) influences fibrin clot properties in atrial fibrillation (AF) remain ill-defined. We aimed to investigate the effects of AF and CKD on fibrin clot properties and lipoproteins, and determine the relationship between these factors. Methods: Prospective cross-sectional study of patients recruited from cardiology services in Liverpool between September 2019 and October 2021. Primary groups consisted of anticoagulated AF patients with and without CKD in a 1:1 ratio. Control group comprised anticoagulated patients without AF or CKD. Fibrin clot properties were analysed using turbidity and permeation assays. Detailed lipoprotein characteristics, including total cholesterol, low-density lipoprotein cholesterol (LDL-C), small dense LDL and oxidised LDL, were measured. Results: Fifty-six anticoagulated patients were enrolled (median age 72.5; 34% female); 46 with AF (23 with CKD and 23 without CKD) and 10 controls. AF was associated with changes in three indices of fibrin clot properties using PTT (Tlag 314 vs. 358 s, p = 0.047; Abspeak 0.153 vs. 0.111 units, p = 0.031; Tlysis50% 884 vs. 280 s, p = 0.047) and thrombin reagents (Tlag 170 vs. 132 s, p = 0.031; Tmax 590 vs. 462 s, p = 0.047; Tpeak50% 406 vs. 220 s, p = 0.005) while the concomitant presence of CKD led to changes in fibrin clot properties using kaolin (Tlag 1072 vs. 1640 s, p = 0.003; Tmax 1458 vs. 1962 s, p = 0.005; Tpeak50% 1294 vs. 2046, p = 0.008) and PPP reagents (Tlag 566 vs. 748 s, p = 0.044). Neither of these conditions were associated with changes in fibrin clot permeability. Deteriorating eGFR was significantly correlated to the speed of clot formation, and CKD was independently associated with unfavourable clot properties (Tlag −778, p = 0.002; Tmax −867, p = 0.004; Tpeak50% −853, p = 0.004 with kaolin reagent). AF alone was not associated with changes in lipoprotein distribution while AF patients with CKD had lower total cholesterol, LDL-C and small dense LDL due to the presence of other risk factors. No significant relationship was observed between fibrin clot properties and lipoprotein distribution. Conclusions: There are important changes that occur in fibrin clot properties with AF and CKD that may account for the increased risk of thromboembolic complications. However, these changes in fibrin clot properties were not attributable to alterations in lipoprotein distribution.

Rifaximin, an antimicrobial used for the treatment of various diseases, lacks analytical methods in official compendia for evaluation of the final product. This paper presents an eco-friendly protocol for rifaximin tablets by high performance liquid chromatography coupled with mass spectrometry (HPLC-MS). The method was completely validated according to the International Conference on Harmonization guidelines and developed following the concept of Quality by Design. The separation was achieved using a C18 column, purified water +0.1% glacial acetic acid and ethyl alcohol, 52:48 (v/v), as mobile phase, 0.9 mL min−1 at 290 nm and ambient room temperature. Mass spectral analyses were performed using electrospray ionization (ESI) ion source and ion trap mass analyzer. The method was linear over the concentration range of 5–50 μg mL−1. The sample was subjected to acidic, basic, neutral, oxidative and photolytic degradation. Degradation products did not interfere in the quantification of the rifaximin, so the method can be considered indicative of stability. Degradation products were also evaluated individually by microbiological method using Escherichia coli. The validated method could be used promisingly as green analytical strategies for detection and quantification of rifaximin in tablets. [ABSTRACT FROM AUTHOR]

Turbidimetry is an experimental technique often used to study the structure of filamentous networks. To extract structural properties such as filament diameter from turbidimetric data, simplifications to light scattering theory must be employed. In this work, we evaluate the applicability of three commonly utilized turbidimetric analysis approaches, each using slightly different simplifications. We make a specific application towards analyzing fibrin fibers, which form the structural scaffold of blood clots, but the results are generalizable. Numerical simulations were utilized to assess the applicability of each approach across a range of fiber lengths and diameters. Simulation results indicated that all three turbidimetric approaches commonly underestimate fiber diameter, and that the “Carr-Hermans” approach, utilizing wavelengths in the range of 500–800 nm, provided

Light scattering and turbidimetry techniques are classical tools for characterizing the dynamics and structure of single nanoparticles or nanostructured networks. They work by analyzing, as a function of time (Dynamic Light Scattering, DLS) or angles (Static Light Scattering, SLS), the light scattered by a sample, or measuring, as a function of the wavelength, the intensity scattered over the entire solid angle when the sample is illuminated with white light (Multi Wavelength Turbidimetry, MWT). Light scattering methods probe different length scales, in the ranges of ~5–500 nm (DLS), or ~0.1–5 μm (Wide Angle SLS), or ~1–100 μm (Low Angle SLS), and some of them can be operated in a time-resolved mode, with the possibility of characterizing not only stationary, but also aggregating, polymerizing, or self-assembling samples. Thus, the combined use of these techniques represents a powerful approach for studying systems characterized by very different length scales. In this work, we will review some typical applications of these methods, ranging from the field of colloidal fractal aggregation to the polymerization of biologic networks made of randomly entangled nanosized fibers. We will also discuss the opportunity of combining together different scattering techniques, emphasizing the advantages of a global analysis with respect to single-methods data processing.

N-acryloyl-L-valine (AV) was synthesized as a pH-sensitive monomer possessing both acrylamide and isopropyl sequences similar to the chemical architecture of N-isopropylacrylamide (NIPAAm). Poly(NIPAAm-co-AV) copolymer contained 5.03 mol % randomly introduced AV units was prepared and analyzed. The sample with molar mass Mw = 24,000 g/mol was studied in aqueous solutions using static and dynamic light scattering and optical transmittance methods. Temperature dependences of scattered light intensity and turbidity as well as hydrodynamic radii of dissolved species and their relative contributions to the light scattering were obtained to determine the temperatures of phase separation in aqueous media of various acidities. The dependence of the phase separation onset temperatures on pH corresponded to that obtained for anionic pH-responsive polymers. Aggregated structures were observed in solutions; moreover, in a strongly acidic medium, with an increase in temperature, the compaction of aggregates predominated, and with an increase in pH, the formation of new aggregates dominated over their compaction. [ABSTRACT FROM AUTHOR]

Featured Application: The combined use of light scattering, turbidimetry, and differential scanning calorimetry highlighted the thermoresponsive self-assembling behavior in water of the oligo(ethylene glycol)-modified pentafluorostyrene homopolymers. The potential applications of such novel smart materials are open to study in advanced fields, including nano-medicine, nano-catalysis and bottom-up nanotechnology at large. Amphiphilic tetrafluorostyrene monomers (EFS8) carrying in the para position an oligoethylene glycol chain containing 8 oxyethylenic units on average were synthesized and used for preparation via activator regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP) of the corresponding amphiphilic homopolymers (pEFS8-x) with different degrees of polymerization (x = 26 and 46). Combining light transmittance and nano-differential scanning calorimetry (n-DSC) measurements revealed that pEFS8-x homopolymers displayed a lower critical solution temperature (LCST) thermoresponsive behavior in water solutions. Moreover, n-DSC measurements revealed the presence in heating scans of a broad endothermic peak ascribable to the dehydration process of the polymer single chains (unimers) and their collapse into aggregates. Consistently, dynamic light scattering (DLS) measurements showed below the LCST the presence of small nanostructures with a hydrodynamic diameter size Dh of 6–7 nm, which collapsed into concentration-dependent larger multichain aggregates (Dh = 300–3000 nm) above LCST. Interestingly, n-DSC data showed that the unimer-aggregate transition was reversible up to a specific temperature (Trev) of each homopolymer, which in any case was higher than Tmax. When heating above Trev the transition was no longer reversible, causing the shift of Tonset and Tmax at lower values, thus suggesting an increase in hydrophobicity of the polymer systems associated with a temperature-dependent dehydration process. [ABSTRACT FROM AUTHOR]

Neonatal sepsis, a condition defined as bacteremia within the first month of life accompanied by signs of systemic infection, is the most preventable cause of infant mortality in sub-Saharan Africa. Despite the development of new infection markers, C-reactive protein (CRP) is the most extensively studied acute phase reactant so far and the preferred index in many neonatal intensive care units (NICUs). The aim of the present study was to evaluate an affordable, non-commercial turbidimetric CRP assay for monitoring early-onset neonatal sepsis (EOS). A total of 148 neonates admitted at the NICU of the Hôpital Provincial Général de Référence de Bukavu to diagnose and to monitor EOS were enrolled in the study. CRP was assayed using a functional turbidimetric assay based on the interaction of CRP with phosphocholine containing particles (Intralipid®). In total, 62/148 (41.9%) cases were identified as blood culture-proven EOS. Different serum CRP slopes were observed among the different birth weight categories. Moreover, the serum (CRP 48 h–CRP 12 h) difference and the birth weight predicted the outcome of these septic newborns. Our turbidimetric CRP assay is a potential novel tool that can be used in the management of EOS in sub-Saharan Africa. The simplicity of the assay and the extremely low price make the CRP method very well suited for developing countries. [ABSTRACT FROM AUTHOR]

Bloodstream infections and antimicrobial resistance are an increasing problem in low-income countries. There is a clear need for adapted diagnostic tools. To address this need, we developed a simple, universal reader prototype that detects bacterial growth in blood culture bottles. Our “turbidimeter” evaluates bacterial growth, based on the turbidity of the broth and the color change of the colorimetric CO2 indicator in commercially available blood culture bottles. A total of 60 measurements were performed using 10 relevant microbial species, spiked in horse blood, to compare the turbidimeter’s performance with that of an automatic reference system. The turbidimeter was able to detect growth in all but one of the spiked blood culture bottles. In the majority (7/10) of the species tested, time-to-detection of the turbidimeter was shown to be non-inferior to the reference automated time-to-detection. This was, however, only the case when both the turbidity and color change in the colorimetric CO2-indicator were used to evaluate growth. We could not demonstrate the non-inferiority of the turbidity measurement alone. Overall, the turbidimeter performed well, but we also identified some improvements that will be implemented in the next version of the prototype.

BACKGROUND: This study investigates the complexation of a pea albumin‐rich fraction and ovalbumin with pectin of different degrees of esterification (DE) and blockiness (DB) as a function of pH and biopolymer mixing ratio by turbidimetric titration and isothermal titration calorimetry (ITC). RESULTS: Turbidimetric analysis found maximum complexation occurred at a mixing ratio of 4:1 for pea albumin with high methoxy pectin, 8:1 for pea albumin with low methoxy pectin, and 8:1 for ovalbumin with low methoxy pectin. In the case of ovalbumin with high methoxy pectin, interactions were very weak. The pectin with high levels of esterification and blockiness displayed greater interactions with the pea albumin in both turbidimetry and ITC. However, low methoxy pectin imparted better interactions with ovalbumin and displayed higher optical density values than high methoxy pectin. CONCLUSIONS: The current study indicated that the different thermodynamic parameters of PA‐pectin complexes can be tuned by controlling the structural characteristics (DB, DE, and d‐galacturonic acid) of the pectin. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The beetroot is widely grown in Brazil, but little is known about its fertilization with sulfur (S). To evaluate the response of the beet culture to different doses of elementary S (0, 30, 60, 90, 120, and 150 kg ha-1), a randomized block experiment was carried out in Cambisol soil distributed in beds with 1,0 m wide x 5.34 m long. The soil pH was corrected to 6.0; and 100 kg ha-1 of N (in two doses), 380 kg ha-1 of P2O5, and 180 kg ha-1 of K2O were applied. The evaluations were carried out at 60 DAS (days after sowing), fresh and dry mass of leaves and roots are used. Subsequently, the tissues were ground and subjected to nitro-perchloric digestion. For the analysis of S in the soil, samples were collected up to 20 cm deep, dried, ground, and sieved in a 2 mm mesh, determining the available S-SO4-2 after nitroperchloric digestion. The S content in the tissue and in the soil was determined in the solution in a spectrophotometer (440nm), by turbidimetry. The beet plants grown in the soil with the addition of 60 kg ha-1 of S showed the highest production of the fresh and dry mass of beetroots. Adequate S levels in the soil were approximately 10 mg dm-3, higher than 5.0 mg dm-3 considered high by the culture recommendation. With the application of 30 kg ha-1 of S it was observed a greater fresh and dry leaf mass, and export of S in leaf and roots. [ABSTRACT FROM AUTHOR]

Collagen type I is a material widely used for 3D cell culture and tissue engineering. Different architectures, such as gels, sponges, membranes, and nanofibers, can be fabricated with it. In collagen hydrogels, the formation of fibrils and fibers depends on various parameters, such as the source of collagen, pH, temperature, concentration, age, etc. In this work, we study the fibrillogenesis process in collagen type I hydrogels with different types of microbeads embedded, using optical techniques such as turbidity assay and confocal reflectance microscopy. We observe that microbeads embedded in the collagen matrix hydrogels modify the fibrillogenesis. Our results show that carboxylated fluorescent microbeads accelerate 3.6 times the gelation, while silica microbeads slow down the formation of collagen fibrils by a factor of 1.9, both compared to pure collagen hydrogels. Our observations suggest that carboxylate microbeads act as nucleation sites and the early collagen fibrils bind to the microbeads., (Creative Commons Attribution license.)

Public concerns about food safety have triggered a worldwide implementation of new legislations aimed at banning many of the most popular food conventional antifungal treatments. There is therefore an urgent need to identify novel and safer solutions to prevent fungal contamination of food. The antifungal effect of zinc oxide nanoparticles (ZnO NPs) against the postharvest pathogenic fungus Penicillium expansum has been investigated in this study. An automated turbidimetric assay, with a standard 96-well microplate, has been developed and optimised regarding the selection of the inoculum size in order to collect sequential optical density measurements. Data were processed by the updated version of the Lambert Pearson model to estimate the minimum inhibitory concentration and the non-inhibitory concentration values which were found to be 9.8 and 1.8 mM (i.e. 798 and 147 ppm), respectively. The current results show that turbidimetry is a reliable technique for assessing the antifungal activity of metal nanoparticles and that zinc oxide (ZnO) is an effective fungicide which can be potentially used to control food safety.

Here, we describe a method to measure turbidity in liquids by probing a graphic pattern by optical transmission. Data are collected by a video camera, and a mathematical algorithm is used to correlate image loss with turbidity. We report high-resolution turbidity measurements of nanoparticle colloids to assess the proposed methodology. Measurements are differentially performed, which helps reduce noise from external sources. Using nephelometric turbidity units (NTU) standards, we obtain detectable measurements in a broad range of NTU from 1.95 to 1000. By implementing the proposed methodology, we proposed a video-based inexpensive yet reliable turbidimetry instrument. [ABSTRACT FROM AUTHOR]

A new series of naphthyl chalcones (3a–3p) and their pyrazoline derivatives (4a–4h) were synthesized using substituted acetophenones, substituted naphthaldehydes, and hydrazine hydrate as starting materials. All the synthesized compounds were characterized by IR, NMR, and mass spectrometric analysis and screened for antimycobacterial activity against Mycobacterium tuberculosis H37Rv (ATCC 27924) and antibacterial activity against Staphylococcus aureus (MTCC 96), Bacillus subtilis (MTCC 441), Escherichia coli (MTCC 443) and Klebsiella pneumonia (MTCC 109). Compounds 3b and 3p exhibited significant antibacterial activity against all the tested bacterial strains. Amongst the synthesized compounds, compound 4b with 2-hydroxy-5-bromophenyl substitution at 3rd position of pyrazoline showed significant antimycobacterial activity with MIC of 6.25 µM comparable to that of standard isoniazid. The synthesized compounds were further screened for their cytotoxic activity against the MDA-MB-231 and SKOV3 cell lines. The compounds 3a, 3l, 4b, 4c, 4e, and 4h did not exhibit any cytotoxicity, and other compounds exhibited IC50 values higher than 8 and 22 µM against MDA-MB-231 and SKOV3 cell lines, respectively, compared to 1.20 and 1.30 µM shown by standard doxorubicin. To find out the putative binding mode of significantly active and weakly active compounds, a molecular docking study was also performed. In that, the most active compound 4b, displayed a hydrogen bond interaction with docking score of −10.50 kcal/mol and energy of −44.50 weakly active compound 3h did not show any crucial hydrogen bond interaction with the surrounded amino-acid residues and revealed a docking score of −6.74 and docking energy of −42.50. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Modern Laboratory Medicine is the property of Journal of Modern Laboratory Medicine Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

suPAR is a plasma marker of chronic inflammation, and an elevated suPAR is consistently associated with worse outcome in a variety of clinical conditions. Quantification of suPAR is useful for determining patient risk in triage, but there is no fast automatized method for quick determination of suPAR. We developed and validated a rapid latex particle-enhanced turbidimetric immunoassay for quantification of plasma suPAR on the c502 and the c702 Roche Cobas® 8000 measurment systems. The turbidimetric assay was validated against the suPARnostic® ELISA (ViroGates, Denmark). This validation demonstrates suPAR can be analysed by turbidimetry giving very similar results (<15% difference) compared to the ELISA method and the observed correlations (n = 103) were strong, r > 0.95. Roche Cobas® 8000 instruments demonstrated repeatability and repoducibility, CV % at 3.4-4.1 and 5.7-11.4, respectively. The estimated limit of detection was 1.30 µg/L and 1.31 µg/L for the Cobas® c502 and c702, respectively. Dilution tests showed linearity of suPAR from 1.8 to 26.5 μg/L. The acceptable concentrations of Bilirubin, Intralipid and Hemoglobin, were 350 µmol/L, 3.3 g/L and 1.4 g/L, respectively. suPAR can be quantified reproducibly within 10 min using a turbidimetry assay. This assay is faster than ELISA with similar results, making it suitable for clinical routine analysis. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: C-reactive protein (CRP) is used as a marker in inflammatory diseases, cardiovascular events, and many cases associated with trauma and inflammation. In this study, different devices and immunonephelometric and immunoturbidimetric method were compared. Material and Methods: Routinely studied 150 CRP samples in BN II System (Siemens, Germany) were included into the study by forming 4 level (<3.28, 3.28-5, 5-10, >10 mg/L). All samples were studied in Immage 800, Architect c16000, Beckman AU680, Cobas C501 devices. Results: When CRP results in BN II System and Immage 800 devices were compared dichotomously, it was found to be a significant difference (p<0.016). With Bonferroni-corrected Mann-Whitney U test, there is a significant difference between the CRP results in immunoturbidimetric Architect c16000, Beckman AU680, Cobas C501 immunonephelometric BN II System devices and immunonephelometric Immage 800 CRP results. There are no significant differences between other device groupings. According to the Bland-Altman analysis, the devices with the minimum mean value of the differences were immunoturbidimetric AU680 and Cobas C501 (-0.9) and immunonephelometric BN II System and immunoturbidimetric Cobas C501 (0.2). Conclusion: We think that the immunoturbidimetric measurement systems are technically superior to immunonephelometric systems, immunoturbidimetric systems provide a more convenient use in terms of labor and economics. [ABSTRACT FROM AUTHOR]

The potential of lysozyme to degrade bacterial cell wall has found important applications in the fields of medicine and biotechnology. The ability of methylene blue dye to bind to the cell walls of bacteria was utilized for development of an assay method for measurement of lysozyme activity. The method was calibrated with the commercial preparation of lysozyme using Micrococcus lysodeikticus cells as substrate. The method was functional over a range of 5–40 U/mL. The method was compared with the conventional turbidimetric method. Sensitivity of the method was similar to turbidimetric method as both the methods could detect lysozyme activity as low as 5 U/mL. Enzyme activity in saliva samples measured by both the methods was comparable and ranged from 1000 to 2100 U/mL. [ABSTRACT FROM AUTHOR]

Thrombosis is a leading cause of death around the world. Fibrin, the protein primarily responsible for clot formation, is formed via cleaving soluble fibrinogen by thrombin with resulting properties varying under different clot forming conditions. This study sought to compare trends across thromboelastography (TEG) and turbidimetry utilizing a simplified fibrinogen/thrombin clot model. Turbidimetry is an optical measure (550 nm) of fibrin clot formation and is widely utilized due to its laboratory accessibility and ease of use. Thromboelastography (TEG) is a specialized viscoelastic technique that directly measures clot strength and is primarily utilized in the clinical setting to assess patients' hemostasis. In these experiments, human and bovine fibrin clots were formed in-vitro by mixing fibrinogen and thrombin under diverse clotting conditions. Increasing thrombin concentration (0 to 10 U/mL), ionic strength (0.05 to 0.3 M), pH (5.5 to 8.1), and lowering albumin concentration (100 to 0 mg/mL) resulted in decreased clot turbidity and increased clot strength using species-matched bovine and human fibrinogen and thrombin. Whereas, increasing fibrinogen concentration (1 to 5 mg/mL) resulted in increased clot turbidity and increased clot strength for both species-matched and cross-species fibrinogen and thrombin. Clotting times with both techniques followed a similar trend and were observed to be unchanged when varying albumin concentration, elongated with increasing fibrinogen, and shortened with increasing pH, ionic strength, and thrombin. TEG and turbidimetry track clot formation via two distinct methods and when utilized together provide complementary clot strength and fiber structural information across diverse clotting conditions. Unlabelled Image • TEG and Turbidimetry are complementary in characterizing fibrin clots. • Clotting times showed a similar trend although mechanisms of the two assays differ. • Clot strength and turbidity are inversely related at the same fibrinogen levels. [ABSTRACT FROM AUTHOR]

Fibrin-d-dimer (d-dimer) is essential for the diagnosis and treatment of thrombosis patients. The new ACL TOP 50- series used for d-dimer determination, integrates a preanalytical interference check for hemolysis, icterus and lipemia (HIL-test). Using earlier versions of ACL TOP, HIL was evaluated by visual inspection by the biomedical laboratory scientist. With the new integrated HIL-test, lipemia is determined by measuring turbidity in the sample at 671 nm, reflecting the lipid content in the sample. Using the new ACL TOP 50- series, we observed more samples being rejected for d-dimer analysis due to lipemia-interference evaluated by the integrated HIL-test suggesting a discrepancy between the former triglyceride-based cut-off and the new turbidity-based cut-off. Therefore, to re-evaluate the lipemia interference cut-off with the turbidimetric measurement, we did a spike-in experiment, using intralipid as lipemia simulation. Three × six different patient pools were prepared from sodium-citrate plasma. We observed no interference in the d-dimer assay by intralipid concentrations resulting in milli absorbances (mAbs) below 3000 mAbs. Thus, the cut-off for lipemia interference using the integrated HIL-test on ACL TOP 550 should be 3000 mAbs. This cut-off will reduce the number of samples rejected due to false positive interference and at the same time reduce 'hands on' time for the biomedical laboratory scientists and minimize the risk of subjective evaluation by a visual inspection. [ABSTRACT FROM AUTHOR]

Background: Age-related macular degeneration (AMD) is a major cause of visual loss in elderly individuals. However, the involvement of cell receptors in the initiation of retinal disorder in AMD has not been duly reflected in the literature. The absence of system analysis of pathogenetic mechanisms of drusen formation restricts the possibilities for researchers to develop methods of treatment and prevention of early AMD. Purpose: To carry out system analysis of novel factors in the pathogenesis of drusen formation in AMD. Material and Methods: This prospective study included 109 patients (186 eyes) with intermediate stage of dry AMD. All patients received a detailed eye examination before and in the course of treatment. We used receptor ligands (specifically, adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine, platelet activation factor (PAF), adrenaline and isadrine) to examine the functional activity of platelet receptors. Platelet aggregation was assessed by the turbidimetric method. The effect of platelet reactivity on the formation of drusen in the RPE was also assessed. Results: The comparison of Group 1 patients with and without drusen (subgroups A and B, respectively) versus controls with regard to platelet reactivity indicated that hyperreactivity of alpha-2 adrenoreceptors reflected early accumulation of metabolite residues in RPE cells and appearance of drusen in the retina. An increase in drusen numbers in the RPE in Group 2 (subgroup C) patients with early dry AMD compared to subgroup B with was reflected by increased activity of P2X purine receptors (p < 0.05) and A2A adenosine receptors (p < 0.001). In group 3 (subgroup E) patients with intermediate stage of dry AMD, an increase in the size of drusen was accompanied by changes in activity of the four examined platelet receptors, with increases in sensitivity of alpha-2 adrenoreceptor, P2X and PAF receptors, and a decrease in sensitivity of beta-2 adrenoreceptor. Conclusion: Platelet receptors reactivity reflected the effect of factors in the pathogenesis of AMD on drusen formation, and, therefore, can be used for prediction of the risk of disease progression. [ABSTRACT FROM AUTHOR]

A turbidimetric method for the determination of total sulfur content in green liquors was developed. The proposed method involves the quantitative conversion of reduced sulfur with hydrogen peroxide to form sulfate at room temperature for 2 min. After barium chloride is added, sulfate instantly reacts with barium chloride to form precipitated barium sulfate that is measured with a UV-Vis spectrophotometer. The interference from carbonate can be eliminated by adding hydrochloric acid. Proper analytical conditions were determined as follows: detection wavelength of 420 nm, the stabilizer of polyvinyl alcohol (PVA), and an analysis time of 10 min. The results showed that the method has an excellent measurement precision (RSD < 1.30%) and accuracy (recovery = 100.1 ± 1.7%) for the quantification of total sulfur content in green liquors. The present method is simple, rapid, and accurate, and can be used for the efficient determination of total sulfur in green liquors. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (T2DM) is associated with hypofibrinolysis and increased factor XIII-mediated α2-antiplasmin incorporation into the fibrin clot. It is unclear whether there are sex-related differences in α2-antiplasmin incorporation in relation to impaired clot lysis in T2DM. We investigated α2-antiplasmin incorporation into fibrin clots as a determinant of clot lysability in patients of both sexes with T2DM. In a group of 113 T2DM patients, 54 (47.8%) of which were women, we investigated α2-antiplasmin incorporation using an in-house sandwich enzyme-linked immunoassay and plasma clot lysis by turbidimetry, along with fibrinogen and thrombin generation using calibrated automated thrombogram and factor XIII activity. Female patients had 15.2% greater α2-antiplasmin incorporation into the fibrin clot (p = 0.008) and slightly higher plasma α2-antiplasmin concentration (p = 0.005) along with 8.4% longer time to 50% lysis (Lys50 MA , p = 0.012) compared with men. Female patients had enhanced thrombin generation represented by shorter lag phase (p = 0.042), shorter time to peak (p = 0.033), and higher endogenous thrombin potential (p = 0.003) compared with men, while factor XIII activity was comparable between sexes (p = 0.085). On multivariate regression, patient sex and glycated hemoglobin (HbA1c) level were the predictors of α2-antiplasmin incorporation in the entire patient group, while α2-antiplasmin incorporation was associated with Lys50 MA , as were fibrinogen, male sex and body-mass index. This study suggests that a more compromised fibrinolysis in diabetic women when compared with men could be in part mediated by increased α2-antiplasmin incorporation into the fibrin. • In type 2 diabetes, α2-antiplasmin incorporation in clot is increased in female patients as compared with male subjects. • Gender and glycated hemoglobin level are predictors of the α2-antiplasmin incorporation in patients with type 2 diabetes. • In type 2 diabetes, α2-antiplasmin incorporation positively correlates with the turbidimetric clot lysis time. [ABSTRACT FROM AUTHOR]

The monitoring of life of microbial populations is of the uttermost importance in environmental and food analysis, agriculture, as well as in medicine. The duration of bacteria adaptation to new environmental conditions, its lifetime and the divisions' pace are the key information in many studies. It was found that the fully-mechanized flow analysis system based on solenoid valves and pumps, paired with a dedicated flow-through optoelectronic detector can be successfully applied for monitoring of bacteria growth. The applicability of the designed multicommutated flow analysis (MCFA) system was proved by analysis of solutions containing bacteria cells proceeded by tests of McFarland (McF) standards. The developed setup allowed modelling and simulation of microbial growth, as well as monitoring of the bacteria growth in real-time manner to be carried out. The monitor is useful for the quantitative estimation of the basic parameters of bacteria population like its size, the rate of bacteria multiplication, as well as the times of lag, log and stationary phases of microbial growth. [Display omitted] • Optoelectronic detector of microbial population size is developed. • The detector is used in microprocessor-controlled flow analysis system. • The system plays the role of real-time-operating monitor of bacterial growth. • The monitor allows the quantitative parameters of bacterial growth to be estimated. [ABSTRACT FROM AUTHOR]

Swellable polymer microspheres that respond to pH were prepared by free radical dispersion polymerization using N-isopropylacrylamide (NIPA), N,N′-methylenebisacrylamide (MBA), 2,2-dimethoxy-2-phenylacetylphenone, N-tert-butylacrylamide (NTBA), and a pH-sensitive functional comonomer (acrylic acid, methacrylic acid, ethacrylic acid, or propacrylic acid). The diameter of the microspheres was between 0.5 and 1.0 μm. These microspheres were cast into hydrogel membranes prepared by mixing the pH-sensitive swellable polymer particles with aqueous polyvinyl alcohol (PVA) solutions followed by crosslinking with glutaric dialdehyde for use as pH sensors. Large changes in the turbidity of the PVA membrane were observed as the pH of the buffer solution in contact with the membrane was varied. These changes were monitored by UV–visible absorbance spectroscopy. Polymer swelling of many NIPA copolymers was reversible and independent of the ionic strength of the buffer solution in contact with the membrane. Both the degree of swelling and the apparent pKa of the polymer microspheres increased with temperature. Furthermore, the apparent pKa of the polymer particles could be tuned to respond sharply to pH in a broad range (pH 4.0–7.0) by varying the amount of crosslinker (MBA) and transition temperature modifier (NTBA), and the amount, pKa, and hydrophobicity of the pH-sensitive functional comonomer (alkyl acrylic acid) used in the formulation. Potential applications of these polymer particles include fiber optic pH sensing where the pH-sensitive material can be immobilized on the distol end of an optical fiber.

Introduction. The results of development of a certified reference material (CRM) of mineral composition of natural water are presented. A solution prepared from the material of the CRM specimen imitates mineral composition of natural surface water. The certified values are mass fractions of nitrate ions, chloride ions, fluoride ions, and total iron and turbidity according to formazine scale. Materials and methods. The certified values of mass concentrations of the components were determined using calculated experimental evaluation procedure;the certified turbidity value was determinedusing the certified turbidimetric method. Results. The relative expanded uncertainty (k = 2) of the certified turbidity values does not exceed 5 %, the same value for mass concentrationsis not more than 3.5 %. Relative standard uncertainty from heterogeneity does not exceed 1.0 %. The shelf life of the developed CRM is set to 3 years. Discussion and conclusion. Developed CRM was registered in the State Register of CRM's as GSO 10815-2016. The CRM is designed to control the accuracy of results of the certified characteristics measurements, including proficiency testing of laboratories using interlaboratory comparative tests. The CRM can be used for validation of measurement procedures.

Most clinical laboratories quantify alpha-1 antitrypsin using either nephelometry or turbidimetry techniques because they are commercially available, amenable to automation, and precise. Both methods are based on light scatter. The foundation of both techniques is based on incubation of the specimen with anti-AAT polyclonal antibody solution, a polymer matrix between endogenous AAT and the reagent antibodies forms, leading to production of light-scattering large particles. Although these two terms are sometimes used synonymously, technically speaking they are not.Nephelometry measures the amount of turbidity or cloudiness of a solution by directly quantifying the intensity of the light scattered by insoluble particles in the sample. Therefore, this technique measures the light that passes through the sample, with the detector being placed at an angle from the sample. Turbidimetry is the process of measuring the loss of intensity of the light transmitted linearly through a sample caused by the scattering effect of insoluble particles. The decrease in light transmission is measured compared to a reference, and the absorbed light is quantified.Beyond specific technical differences between both techniques, there are two major differences between the two procedures that may influence the results. First, the concentration of the sample and the resulting intensity of scattered light relative to the intensity of the light source is one major factor. Second, the size of the scattering particles is also a key differentiating factor. This chapter describes the technical requirements, the different protocols, and the clinical applicability of these two techniques in the diagnosis of alpha-1 antitrypsin deficiency., (© 2024. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

To obtain insight into physicochemical interactions between Cu(II) ions, kaolinite, and exopolysaccharide (EPS) synthesized by Sinorhizobium meliloti Rm 1021 soil bacteria, an adsorption, electrokinetic, and aggregation study was performed in the selected systems. The obtained data showed that supporting electrolyte type affects both EPS and Cu(II) ions adsorption. For initial Cu(II) concentration 100 mg/L, 4.36 ± 0.25 mg/g (21.80 ± 1.00%) of the ions were adsorbed in 0.001 M NaCl and 3.76 ± 0.20 mg/g (18.80 ± 1.00%) in 0.001 M CaCl2. The experimental data were best fitted to the Langmuir model as well as pseudo second-order equation. The EPS adsorbed amount on kaolinite was higher in the CaCl2 electrolyte than in NaCl one. For an initial polymer concentration of 100 mg/L, the EPS adsorbed amount was 4.69 ± 0.08 mg/g (23.45 ± 0.40%) in 0.001 M NaCl and 5.26 ± 0.15 mg/g (26.32 ± 0.75%) in 0.001 M CaCl2. In the mixed system, regardless of electrolyte type, exopolysaccharide contributed to immobilization of higher amount of copper(II) ions on the clay mineral. Also, in the samples containing heavy metal ions and exopolysaccharide simultaneously, the aggregation of kaolinite particles was the strongest. The results presented in the paper may be very helpful in soil bioremediation, especially in the development of technologies reducing the mobility of heavy metals in the environment.

Turbidimetric assays with latex nanoparticles are widely applied for the detection of biological analytes, because of their rapidity, low cost, reproducibility, and automatization. However, the detection limit can be lowered only at the price of a reduced dynamic range, due to the rapid saturation of the light scattering signal at high analyte concentration. Here, we use numerical calculations to investigate the possibility of increasing the performance of immuno-turbidimetric assays without compromising the measurement dynamic range, by combining plasmonic (gold, silver) and latex nanoparticles. Our modelling results show that plasmonic nanoparticles are compatible with a large signal change even when small aggregates are formed, i.e., at low analyte concentration. The working principle relies on the remarkable modification of the surface plasmon band when noble metal nanoparticles form oligomers, and also when latex particles are included in the aggregate. At high analyte concentration, when larger aggregates form, the latex particles can provide the required linear response of standard immuno-turbidimetric assays. Thus, the combination of the two components can be a successful strategy to improve the detection limit and the dynamic range, while maintaining all the advantages of the homogeneous immuno-turbidimetric assays.

The behavior of star-shaped six-arm poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines in aqueous solutions on heating was studied by light scattering, turbidimetry and microcalorimetry. The core of stars was hexaaza [26] orthoparacyclophane and the arms were poly-2-ethyl-2-oxazine, poly-2-isopropyl-2-oxazine, poly-2-ethyl-2-oxazoline, and poly-2-isopropyl-2-oxazoline. The arm structure affects the properties of polymers already at low temperatures. Molecules and aggregates were present in solutions of poly-2-alkyl-2-oxazines, while aggregates of two types were observed in the case of poly-2-alkyl-2-oxazolines. On heating below the phase separation temperature, the characteristics of the investigated solutions did not depend practically on temperature. An increase in the dehydration degree of poly-2-alkyl-2-oxazines and poly-2-alkyl-2-oxazolines led to the formation of intermolecular hydrogen bonds, and aggregation was the dominant process near the phase separation temperature. It was shown that the characteristics of the phase transition in solutions of the studied polymer stars are determined primarily by the arm structure, while the influence of the molar mass is not so significant. In comparison with literature data, the role of the hydrophobic core structure in the formation of the properties of star-shaped polymers was analyzed.

Amphiphilic tetrafluorostyrene monomers (EFS8) carrying in the para position an oligoethylene glycol chain containing 8 oxyethylenic units on average were synthesized and used for preparation via activator regenerated by electron transfer atom transfer radical polymerization (ARGET-ATRP) of the corresponding amphiphilic homopolymers (pEFS8-x) with different degrees of polymerization (x = 26 and 46). Combining light transmittance and nano-differential scanning calorimetry (n-DSC) measurements revealed that pEFS8-x homopolymers displayed a lower critical solution temperature (LCST) thermoresponsive behavior in water solutions. Moreover, n-DSC measurements revealed the presence in heating scans of a broad endothermic peak ascribable to the dehydration process of the polymer single chains (unimers) and their collapse into aggregates. Consistently, dynamic light scattering (DLS) measurements showed below the LCST the presence of small nanostructures with a hydrodynamic diameter size Dh of 6–7 nm, which collapsed into concentration-dependent larger multichain aggregates (Dh = 300–3000 nm) above LCST. Interestingly, n-DSC data showed that the unimer-aggregate transition was reversible up to a specific temperature (Trev) of each homopolymer, which in any case was higher than Tmax. When heating above Trev the transition was no longer reversible, causing the shift of Tonset and Tmax at lower values, thus suggesting an increase in hydrophobicity of the polymer systems associated with a temperature-dependent dehydration process.

The structural response to temperature and pH changes of poly-l-lysine (PLL) has been studied by a variety of experimental methods including turbidimetry, dynamic light scattering, and Zeta potential analysis. The experimental results and the molecular dynamics simulations showed that the PLL structural transitions were a result of a competition between electrostatic repulsion, which promotes an extended state, and the hydrophobic effect, which favors a compact state. In fact, as the pH was decreased, the PLL conformation changed from α-helix to the random coil and the hydrophilic volume increases resulted in a transition to spherical micelles which then swelled due to charge-charge repulsions. Following a rise in temperature and/or at high pH, PLL undergoes the α-helix-to-β-sheet transition and reacted more rapidly to form hydrophobic aggregates. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop and validate a simple, new and efficient method for the analysis of hydrogen sulphide (H2S) released from the effluents of phosphoric acid production units. H2S sampling was performed by absorption of the industrial gas into a cadmium acetate absorbing solution. The formed cadmium sulphide (CdS), as a result of a chemical reaction, was analysed by turbidimetry. A methodical validation study of the proposed method was performed according to the requirements of ISO 17025 standards. The proposed method was demonstrated to be precise, linear and accurate over a concentration range of 6.91–92.16 mg/l. Detection and quantification limits were equal to 5.09 mg/l and 6.91 mg/l, respectively. Sample analysis had to be performed within 48 h of the sampling step. The turbidimetry method was applied successfully to the industrial gaseous effluents and can be considered as an economical alternative to the iodometric method. [ABSTRACT FROM AUTHOR]

Specimen lipemia is a primary concern with turbidimetric and nephelometric assays due the potential interference caused by light scattering or absorption. The purpose of this study was to evaluate lipemic interference thresholds across seven FDA-cleared assays using patient specimens with varying degrees of endogenous lipemia pre- and post-ultracentrifugation (UC) and with Intralipid spiking. Using an IRB-approved protocol, residual human serum specimens (n=42; L-indices, 1-1769; H-index ≤85; I-index ≤2) were obtained. Baseline and post-UC testing was conducted across assays on cobas c502 and c702 instruments (Roche Diagnostics; Indianapolis, IN). Serum indices and triglyceride (TRIG) concentrations were also measured pre- and post-UC. Intralipid spiking studies with human AB serum were also conducted. Lipoprotein subfraction analysis (Lipoprint; Quantimetrix; Redondo Beach, CA) was performed on three additional patient specimens with elevated TRIG post-UC to determine which TRIG-containing lipoprotein fraction(s) remain. Several assays showed L-index thresholds derived from endogenously lipemic specimens that were below previously defined limits from the package inserts (PIs) [new (prior)]: AAT 400 (500); CERU 100 (200); HAPTO 450 (600); TRSF 250 (500). L-index limits derived from Intralipid spiking were generally higher than those listed in PIs. UC did not adversely impact results in non-lipemic or lipemic specimens. UC was effective at clearing lipemic interference, although persistence of residual VLDL was often observed. This study provides an analysis of L-index thresholds for seven immunoturbidimetric assays. Due to the variety of human lipoproteins, limits defined using endogenously lipemic patient specimens may be different from those derived from spiking studies using Intralipid. • Lipemic interference thresholds were evaluated across seven FDA-cleared assays. • Endogenously lipemic specimens and Intralipid were used to evaluate interference. • Interference patterns and thresholds often differed based on the source of lipemia. • UC did not adversely affect results for non-lipemic or Intralipid-spiked specimens. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Cr 2 O 3 suspension stability in ionic PAMs presence was determined using turbidimetry. • Mixed adsorption layers of AN PAM + CT PAM are formed at interface. • Mixture of adsorbates causes increase in removal efficiency of Cr 2 O 3. • Dual-polymer flocculation occurs in suspensions containing both form of ionic PAM. • AN PAM + CT PAM complexes adsorption affects electrokinetic properties of particles. Abstract The main purpose of experiments was determination of the adsorption mechanism of two forms of ionic polyacrylamide (PAM) on the surface of chromium(III) oxide dispersed in the aqueous medium. This was performed in relation to anionic polyacrylamide (AN PAM) and cationic one (CT PAM) in the simple systems (containing only one selected polymer) and in the mixed systems (containing both ionic forms of PAM). The turbidimetry was applied to determine the stability of examined suspensions. To explain the obtained changes in suspension stability after the polymer addition, polyacrylamide adsorbed amount, surface charge density and zeta potential of solid particles were determined. It was found that the solution pH, order of both adsorbates addition as well as the time interval between the AN and CT PAM addition have considerable influence on the structure of polymeric adsorption layer formed on the Cr 2 O 3 surface. It was also proved that changes in the PAM adsorbed amount in the systems containing mixed adsorbates result from formation of AN PAM - CT PAM complexes. They are bounded at the interface in the formed multilayer. As a result, the dual-polymer flocculation occurs more effectively than the destabilization process in the suspensions containing only one type of adsorbate. [ABSTRACT FROM AUTHOR]

Background/Aims: Fecal calprotectin (Fcal) as well as the fecal immunochemical test (FIT) are useful biomarkers for detecting activity and mucosal healing in inflammatory bowel diseases. Here, we report the performance of simultaneous measurements of Fcal and FIT for ulcerative colitis (UC) patients using the newly-developed latex agglutination turbidimetric immunoassay (LATIA) system. Methods: Fcal and hemoglobin were measured by the LATIA system in 152 UC patients who underwent colonoscopy. Fcal was also quantified with a conventional enzyme-linked immunosorbent assay (ELISA). Fecal markers were evaluated in conjunction with the mucosal status of UC, which was assessed via the Mayo endoscopic subscore (MES) classification. Results: The LATIA system could quantify calprotectin and hemoglobin simultaneously with the same fecal samples within 10 minutes. The values of the Fcal-LATIA closely correlated with those of the Fcal-ELISA (Spearman rank correlation coefficient, r=0.84; P<0.0001). The values of Fcal for each assay and the FIT all significantly correlated with the MESs (Spearman rank correlation coefficient, Fcal-LATIA: r=0.58, Fcal-ELISA: r=0.55, and FIT: r=0.72). The mucosal healing predictability (determined by an MES of 0 alone) of the Fcal-LATIA, Fcal-ELISA, and FIT-LATIA with the cutoffs determined by receiver operating characteristic curve analysis was 0.79, 0.78, and 0.92 for sensitivity, respectively, and 0.78, 0.69, and 0.73 for specificity, respectively. Conclusions: The performance of the novel Fcal-LATIA was equivalent to that of the conventional Fcal assay. Simultaneous measurements with FITs would promote the clinical relevance of fecal biomarkers in UC. [ABSTRACT FROM AUTHOR]

Highlights What is known on this topic? • Blood levels of various fatty acids are emerging as modifiable biomarkers for chronic diseases such as CVD. • Blood fatty acids can contribute to CVD via its effects on thrombus structure and composition. • Specific effects of individual fatty acids on clot properties are, however, contradictory and inconsistent because of differences in study designs. What this paper adds? • Plasma phospholipid fatty acids associated with both prothrombotic and profibrinolytic clot phenotypes in a population-based study - these associations were partly mediated by fibrinogen and BMI. • Individual fatty acids from the same composite group often presented opposing associations with clot properties. Abstract Evidence regarding the relationship of plasma clot properties with fatty acids is contradictory, owing to different experimental protocols employed. The relationship of fibrinogen and plasma fibrin clot properties with plasma phospholipid fatty acids were cross-sectionally investigated in a population-based setting in 900 individuals. Composite saturated fatty acids (driven by stearic acid) and composite n-3 and n-6 polyunsaturated fatty acids (driven by docosahexaenoic and arachidonic acid respectively) were associated with prothrombotic clot properties. Composite monounsaturated fatty acids (driven by oleic acid) were associated with a profibrinolytic clot phenotype. Fibrinogen and BMI partly mediated these relationships. Individual plasma fatty acids from the same composite group had opposing associations with clot properties indicating that associations with composite fatty acid groups is dependent on the relative composition of the comprising fatty acids. The relationship of the plasma phospholipid fatty acid profile with disease should not be interpreted without considering the role of regulatory mechanisms. [ABSTRACT FROM AUTHOR]

Background. Histidine-rich glycoprotein (HRG) displays anticoagulant and antifibrinolytic properties in animal models, but its effects in humans are unclear. We investigated serum HRG levels and their associations with the disease stage and prothrombotic alterations in lung cancer (LC) patients. Methods. In 148 patients with advanced LC prior to anticancer therapy (87 non-small-cell LC and 61 small-cell LC) versus 100 well-matched controls, we measured HRG levels in association with clot permeability (Ks), clot turbidimetry (lag phase and maximum absorbance), and clot lysis time (CLT). Results. Compared to controls, LC patients had 45.9% lower HRG levels with no associations with demographics and comorbidities. Decreased HRG, defined as the 90th percentile of control values (<52.7 μg/ml), was 16 times more common in subjects with than without LC (OR=16.4, 95% CI 9.2-23.5, p<0.01). HRG<38 μg/ml discriminated stage IIIAB/limited disease from IV/extensive disease (ED) LC. In LC patients, HRG correlated inversely with CLT (r=−0.41, p<0.001), but not with other fibrin variables. Among stage IV/ED LC, HRG correlated significantly with Ks and lag phase (r=0.28 and r=0.33, respectively, both p<0.001). LC patients with low Ks (10th percentile of control values) combined with prolonged CLT (90th percentile of control values) had reduced HRG levels compared to the remainder (p=0.003). No such observations were noted in controls. Conclusions. Our study is the first to show that decreased HRG levels occur in advanced LC and are associated with the disease stage and hypofibrinolysis. [ABSTRACT FROM AUTHOR]

Highlights • The GoldMag® immunochromatography provide results more stable. • The sensitivity can reach picogram level regardless whole blood and plasma specimens. • This method especially suitable for township hospitals and community. • The assay provides faster and more accurate results for clinical diagnosis. Abstract Objective To investigate the consistency between GoldMag® immunochromatography and immune scatter turbidimetry in hs-CRP detection. Methods The data of hs-CRP were collected from 78 hospitalized patients, and these patients were divided into fingertip blood group and the venous blood group according to the different blood collection methods. The whole blood and plasma level of hs-CRP was detected by GoldMag® immunochromatography and immune scatter turbidimetry. Correlation analysis was carried out to compare the data of hs-CRP obtained by different approaches. Results In both fingertip blood group and venous blood group, the concentration of hs-CRP determined by GoldMag® immunochromatography were positively correlated with those found with immune scatter turbidimetry. There was no significant difference in the level of hs-CRP provided by these two different approaches. (P > 0.05). Conclusion GoldMag® immunochromatographic assay has good uniformity with immune scatter turbidimetry Scatter Turbidimetric Method for hs-CRP detection. Based on the double antibody sandwich method, antibody labeled GoldMag nanoparticles capture hs-CRP from whole blood or plasma and aggregate in test line of test strip. The magnetic intensity of agglomerated GoldMag® nanoparticles collected is measured by magnetic quantitative immunoassay analyzer. The concentration of hs-CRP can be obtained according to the standard curve between concentration and magnetic intensity. GoldMag® immunochromatography is served as an easy operation, high accuracy and stable method. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Synthesized bio-based polyesteramide polyol from algae oil and ricinoleic acid as renewable sources. • Silver doped hydroxyapatite nanoparticles (Ag-HAP NPs) were prepared by utilizing waste chicken egg-shells as third renewable component. • Development of antimicrobial and anticorrosive PU nanocomposite coatings using silver doped hydroxyapatite nanoparticles (Ag-HAP NPs). • Bio-based PU nanocomposite coatings showed good anticorrosive and antimicrobial properties. • In the case of prepared PU nanocomposite coatings, on increasing percentage of Ag-HAP NPs, coatings properties were enhanced. • Algae oil is clean and green source to replace petroleum sources. Abstract Petroleum products need to be replaced by renewable materials because of their ecological impact due to their non-degradable nature and tendency to shortages and price fluctuation. The present investigation reports the preparation of polyesteramide polyol (PEA-RIC) from renewable sources like algae oil and ricinoleic acid from castor oil. It was characterized by 1H NMR and FT-IR spectroscopic techniques, while molecular weight was determined by size exclusion chromatography. Silver doped hydroxyapatite nanoparticles (Ag-HAP NPs) prepared using waste chicken egg-shells were incorporated uniformly in PEA-RIC and their morphology was studied by scanning electron microscopy. Polyol containing Ag-HAP NPs was cross linked using diisocyanate to obtain polyurethane (PU) nanocomposite coatings. Their anticorrosion performance was studied by potentiodynamic polarization (PDP) method while antibacterial activity was measured against Gram-negative (E. coli) and positive (S. aureus) bacteria. These nanocomposite coatings on metallic substrate inhibited both bacteria when checked by turbidimetric method and interestingly exhibited good resistance to bacterial adhesion and bio-film formation as evidenced by SEM analysis. These coatings showed improved hydrophobicity, adhesion, anticorrosive properties and chemical resistance as compared to PU without nanoparticles.. Thermal stability and Tg were found to improve with increasing concentration of Ag-HAP NPs when checked by TGA and DSC. Such coating originating from renewable materials exhibits high applicability in curbing the losses due to corrosion and assists sustainable development. [ABSTRACT FROM AUTHOR]

A series of poly(N,N-diethylacrylamide) samples with low molecular weights (1.9 × 103-5.3 × 104) and narrow polydispersities (below 1.5 and usually lower than 1.25) was synthesized by reversible addition-fragmentation chain transfer polymerization. The phase separation behavior of poly(N,N-diethylacrylamide) in aqueous solution was investigated by turbidimetry, fluorescent probe technology and DSC. It is interesting to find that the lower critical solution temperature (LCST) of the samples increases with increasing molecular weight and remains more or less a constant above a critical molecular weight of 1.2 × 104. At the same time, an inverse dependence of LCST on the concentration was found and this effect was more pronounced for lower molecular weight. To further investigate the novel molecular weight dependence of the LCST, the fluorescent probe study was conducted and the experimental results demonstrated that there was an increase in hydrophobicity when decreasing the molecular weight and increasing the concentration and flower-like micelles were probably formed which can further be proved by TEM. [ABSTRACT FROM AUTHOR]

Calprotectin in plasma and blood might prove to be a useful biomarker of inflammation and infection; however, automated methods for analysing the concentration of calprotectin in those materials are lacking. We have validated a fully automated turbidimetric method and present health-related reference limits. Calprotectin was measured by Siemens Advia XPT with the Bühlmann fCAL® turbo test (Bühlmann Laboratories AG, Schönenbuch, Switzerland), a particle enhanced turbidimetric immunoassay for quantification of calprotectin in fecal extracts. Plasma and serum samples were analysed directly, while whole blood was first extracted with M-PER® Mammalian Protein Extraction Reagent (ThermoFisher) and diluted with B-CAL-EX (Bühlmann). We studied analytical imprecision, estimated health-related reference limits and examined the correlation between neutrophil-calprotectin (blood-calprotectin adjusted for plasma-calprotectin) and the neutrophil count. The intermediate ('day-to-day') coefficient of variation was 3.5 and 1.0% for heparin-plasma-calprotectin at 0.52 mg/L and 3.53 mg/L, respectively, and 4.9% for heparin-blood-calprotectin at 50.2 mg/L. Health-related reference limits were 0.470-3.02 mg/L for calprotectin in heparin-plasma, 50.8-182 mg/L for calprotectin in heparin-blood, 0.534-2.41% for the ratio between them and 24.7-33.3 pg for the mean amount of calprotectin per neutrophil. Compared to heparin-plasma, calprotectin concentrations were significantly lower in EDTA-plasma and higher in serum (p < .05). Correlation between neutrophil-calprotectin and the neutrophil count was excellent. We have shown that the Bühlmann fCAL® turbo test can be used to measure calprotectin in plasma and blood. [ABSTRACT FROM AUTHOR]

Aim. To investigate an ability of HBD-2 to induce aggregation of erythrocytes. Methods. Aggregation assay, turbidimetry, light microscopy. Results. We have identified aggregation of erythrocytes in the presence of at least 12.5 μM HBD-2 that was confirmed by light microscopy. Effect was strongly depended on HBD-2 concentration but was masked by hemolysis of erythrocytes. Also, aggregation was diminished in presence even 10 mM of NaCl that may indicate electrostatic nature of interactions between HBD-2 and erythrocytes. Conclusions. HBD-2 can induce the salt-sensitive aggregation of erythrocytes in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Abstract Pure Na+ forms of furcellaran (β/κ-hybrid carrageenan), κ-carrageenan, κ/ι-hybrid carrageenan, ι-carrageenan and a hybrid carrageenan mix (made up of κ-, ι-, λ- and ν-carrageenans) were tested as beer wort fining agents. To find out which of the used carrageenans are the best beer wort clarifiers and whether they are prone to overdosage, polysaccharides with varying concentrations and molecular weights were tested. The polysaccharides were characterized by 1H NMR spectroscopy and size-exclusion chromatography. The fining efficiency of the tested polysaccharides was measured nephelometrically. Ultrasonicated and alkali treated carrageenan preparations were tested as beer wort fining agents and compared to the native samples. Undegraded furcellaran, κ-carrageenan and κ/ι-hybrids were efficient in lowering the turbidity of various beer worts, but the addition of ι-carrageenan and the carrageenan mix caused the turbidity to rise above the unfined sample value. Compared to the degraded samples, native galactans were more effective in lowering the beer wort turbidity. Higher concentrations of ultrasonicated carrageenans are needed to clarify the beer wort to similar turbidity values. Alkali treated carrageenans were more efficient beer wort fining agents compared to the native samples. Graphical abstract Image Highlights • Native hybrid carrageenan mix and ι-carrageenan increase the beer wort turbidity. • Native carrageenans are more effective in beer wort fining than degraded samples. • Alkali treatment of carrageenans increases the beer wort clarifying potential. • β/κ-, and κ/ι-hybrid carrageenans are very effective beer wort fining agents. [ABSTRACT FROM AUTHOR]