Search results for "Nephelometry"
showing 6 items of 16 documents
Easy-use and low-cost fiber-based two-color dynamic light-scattering apparatus
2011
We present a small and compact two-color cross-correlation light-scattering setup designed to study the structure and dynamics of colloidal suspensions in the regime of considerable turbidity. Using a homemade concentric four-arm goniometer, combined with fiber-optical illumination and detection devices, allows an easy and long time stable alignment-even under a temperature variation of ∼5 °C. Tests with a nearly multiple scattering free suspension of small Rayleigh scatterers show intercepts in cross correlation near 0.4 over a wide range of scattering angles from 20° to 150°. Measuring slightly turbid samples in cross-correlation mode multiple scattering is sufficiently suppressed allowin…
Interpolymer complex between hydroxypropyl cellulose and maleic acid-styrene copolymer: phase behavior of semi-dilute solutions.
2005
Summary: The phase behavior of a water/hydroxypropyl cellulose/maleic acid–styrene copolymer (H2O/HPC/MAc-S) system was investigated in the semi-dilute range by turbidimetry, rheology, and optical microscopy. The two polymers under investigation form interpolymer complexes via hydrogen bonding. In the case of a total polymer concentration of cpol = 5 mg · mL−1 a second phase segregates upon heating the homogeneous ternary system. By applying a constant shear rate ( = 50 s−1) the phase separation temperature of the system is 10–15 °C lower than for an unsheared one. For cpol = 10 mg · mL−1 phase separation has already occurred at room temperature when the two binary polymer solutions are mix…
The role of serum free light chain as biomarker of Myasthenia Gravis
2022
Background and aim: Myasthenia gravis (MG) is a B lymphocyte–mediated disease affecting neuromuscular transmission. The clinical course of MG is unpredictable due to the fluctuating nature and heterogeneity of the disease. Increased levels of free light chains (FLC), which reflect B cell activation, have been detected in different autoimmune disorders. In this study, we evaluated the potential role of FLC as diagnostic and prognostic biomarkers of MG. Materials and methods: 74 MG patients and 52 healthy individuals were included in the study. Serum FLC levels were measured by turbidimetric assay (Freelite, The Binding Site Group Ltd) on the Optilite Analyser System in both groups. In MG pat…
Immunonephelometric determination of the apolipoprotein A-II.
1989
A fully mechanized immunonephelometric method is described for the rapid and specific determination of apolipoprotein A-II in serum. The method utilizes commercially available sheep antiserum against human apolipoprotein A-II. Nephelometry was performed with the Behring Nephelometer Analyzer (BNA). A single determination can be performed in 12 minutes, requiring 10 microliters sample volume. The measuring range is about 0.08 to 1.25 g/l apolipoprotein A-II. Precision is characterized by intra-assay coefficients of variation of 3.37%, 3.93% and 4.49% for apolipoprotein A-II concentrations of 1.22 g/l, 0.376 g/l and 0.185 g/l, and inter-assay coefficients of variation of 4.27% for an apolipop…
Methodologies for the Determination of Blood Alpha1 Antitrypsin Levels: A Systematic Review
2021
Background: The study of hematic concentrations of alpha1 antitrypsin (AAT) is currently one step in the diagnosis of AAT deficiency. To try to clarify the relevance of the laboratory techniques, we carried out a systematic review of the literature. Methods: Studies evaluating the quantification of AAT in peripheral blood were searched in PubMed in July 2021. The selection criteria included (1) any type of study design that included a quantification of AAT in peripheral blood; (2) studies written in English or Spanish; (3) studies evaluating human beings; and (4) studies involving adults. Results: Out of 207 studies, the most frequently used techniques were nephelometry (43.9%), followed by…
D-dimer testing: advantages and limitations in emergency medicine for managing acute venous thromboembolism
2007
Patients with suspected deep vein thrombosis (DVT) or pulmonary embolism (PE) are frequently admitted to an Emergency Department (ED) for initial evaluation. However, management of patients with suspicion of acute venous thromboembolism (VTE) in this clinical setting can be difficult; in fact symptoms and signs of DVT are non-specific and can be found in a broad spectrum of non-thrombotic disorders. An accurate and timely objective diagnosis is necessary for immediate and correct identification of patients with acute VTE, while avoiding the bleeding risk associated with unnecessary anticoagulant therapy in patients where DVT or PE have been ruled out. The diagnostic approach to patients wit…