scholarly journals Diagnostic biomarkers in tear fluid: from sampling to preanalytical processing

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Franziska Bachhuber ◽  
André Huss ◽  
Makbule Senel ◽  
Hayrettin Tumani
Keyword(s):  
Tear Fluid ◽  
Absolute Amount ◽  
Moderate Correlation ◽  
Capillary Tubes ◽  
Flow Rates ◽  
Diagnostic Biomarkers ◽  
Sample Composition ◽  
Tear Flow ◽  
Collection Methods ◽  
Fluid Sampling

AbstractTear fluid is receiving growing attention as a source for novel diagnostic biomarkers. Multiple techniques are available for its collection and impact the composition of acquired samples. We sought to provide a direct comparison of two collection methods with regard to implementation, acceptance, and impact on sample composition. Tear fluid was collected from fifteen healthy volunteers with capillary tubes and Schirmer strips and analyzed for total protein and IgG concentrations. Sampling parameters and perception by test persons were compared. The use of capillary tubes was more convenient for the participants while causing more effort for the collector. Tear flow rates as well as the relative and absolute amount of IgG were higher when Schirmer strips were used. Consecutive collections with Schirmer strips significantly influenced tear flow rates, IgG, and protein concentrations. A moderate correlation was observed between tear flow rates and IgG concentrations for both methods. Samples collected with both methods can be analyzed by isoelectric focusing, a potential diagnostic application in the field of neurology. The specific advantages and limitations of tear fluid sampling with either capillary tubes or Schirmer strips demonstrate the need for a thorough investigation of collection methods with regard to the application of interest.

scholarly journals Comparison of Capillary and Schirmer Strip Tear Fluid Sampling Methods Using SWATH-MS Proteomics Approach

2020 ◽  
Vol 9 (3) ◽  
pp. 16 ◽  
Author(s):  
Janika Nättinen ◽  
Ulla Aapola ◽  
Antti Jylhä ◽  
Anu Vaajanen ◽  
Hannu Uusitalo
Keyword(s):  
Sampling Methods ◽  
Tear Fluid ◽  
Proteomics Approach ◽  
Fluid Sampling

Normal bovine tear flow rates

1982 ◽  
Vol 33 (2) ◽  
pp. 262-263 ◽  
Author(s):  
D.H. Slatter ◽  
M.E. Edwards
Keyword(s):  
Flow Rates ◽  
Tear Flow

Assessment of a Simpler Friction Factor in an Algebraic Solution for Adiabatic Coiled Capillary Tubes

2020 ◽  
Vol 28 (04) ◽  
pp. 2050033
Author(s):  
Thiago Torres Martins Rocha ◽  
Sara Isabel De Melo Resende ◽  
Hélio Augusto Goulart Diniz ◽  
Fernando Antônio Rodrigues Filho ◽  
Raphael Nunes De Oliveira
Keyword(s):  
Friction Factor ◽  
Algebraic Solution ◽  
Maximum Deviation ◽  
Empirical Correlations ◽  
Capillary Tubes ◽  
Average Deviation ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Rms Error ◽  
Dimensionless Correlations

In this work, the performance of an existing algebraic solution for adiabatic coiled capillary tubes, in subcritical cycles, is investigated. However, the C-M&N friction factor, commonly used, was replaced by Schmidt friction factor, which is less complex. Two existing dimensionless correlations were also evaluated for comparison. To assess the effect of altering the friction factor, experimental data collected in the literature were used as reference. Analyzing the present results and that with C-M&N friction factor, it was observed that adopting the Schmidt friction factor does not cause a relevant impact on the solution. The deviations of the predicted versus experimental mass flow rates were comprised in a range between –8% and 12%, with average deviation (AD), absolute average deviation (AAD) and root mean square (RMS) error of –0.1%, 2.7% and 3.4%, respectively. The empirical correlations presented unsatisfactory results, with maximum deviation around 40%. Therefore, it was concluded that using the Schmidt friction factor is adequate to reduce the complexity of the algebraic solution and to maintain the accuracy.

Experiments with constrained chimney-plume flows in the system ammonium chloride–water: comparison with the unconstrained case

1999 ◽  
Vol 388 ◽  
pp. 21-48 ◽  
Author(s):  
SHAN LIU ◽  
ANGUS HELLAWELL
Keyword(s):  
Ammonium Chloride ◽  
Mushy Region ◽  
Capillary Tubes ◽  
Flow Rates ◽  
Dendritic Array ◽  
Naturally Occurring ◽  
Glass Tubes ◽  
Chloride Water ◽  
Thin Walled ◽  
Plume Flows

Thermo-solutal chimney-plume flows from a solidifying dendritic mushy region have been promoted in thin-walled glass tubes of internal radii from 0.3 mm–2.0 mm. Flow rates, liquid compositions and temperatures were measured as functions of the depth of immersion of capillary tubes in the advancing mushy region. The results demonstrate competition between buoyancy pressures and the restrictions of liquid recirculation within the dendritic array and have been analysed to provide permeability data for the mushy region at high liquid fractions. These data have been used to make some assessments of channel/plume dimensions for naturally occurring, unconstrained flows in the same system.

EXPERIMENTAL INVESTIGATION OF R134a FLOWING THROUGH ADIABATIC HELICALLY COILED CAPILLARY TUBES

2012 ◽  
Vol 20 (01) ◽  
pp. 1250001 ◽  
Author(s):  
JATUPORN KAEW-ON ◽  
SAKARIN CHINGULPITAK ◽  
SOMCHAI WONGWISES
Keyword(s):  
Mass Flow ◽  
Flow Characteristic ◽  
Flow Conditions ◽  
Capillary Tubes ◽  
Local Pressure ◽  
Flow Rates ◽  
Temperature Distributions ◽  
Coil Diameter ◽  
Copper Tubing ◽  
Mass Flow Rates

The effects of the relevant parameters on the flow characteristic of R134a flowing through adiabatic helical capillary tubes were experimentally studied. The capillary tubes' diameter, coil diameter, and parameters relating to flow conditions such as inlet pressures and degree of subcooling were the major parameters investigated. The test section was made from copper tubing with inner diameters of 1.07, 1.27, and 1.62 mm. The coil diameters were 25, 50, and 100 mm. The local pressure and temperature distributions along the length of the capillary tubes were measured at inlet pressures ranging from 10 to 14 bar, mass flow rates from 8 to 20 kg/h, and degrees of subcooling from 0.5°C to 15°C. The metastable flow and the delay of vaporization of R134a are also presented and discussed. The results showed that the capillary diameter had more of a significant effect on the mass flow rate than the other variables.

Tear fluid collection methods: Review of current techniques

2021 ◽  
pp. 112067212199892
Author(s):  
Janusz Pieczyński ◽  
Urszula Szulc ◽  
Joanna Harazna ◽  
Aleksandra Szulc ◽  
Jolanta Kiewisz
Keyword(s):  
Chemical Analysis ◽  
Fluid Collection ◽  
Database Search ◽  
Tear Fluid ◽  
Physical Analysis ◽  
Conduct Literature ◽  
Sample Collection ◽  
Pubmed Database ◽  
Tear Analysis ◽  
Collection Methods

Tear fluid, composed of lipid, aqueous, and mucin layers, contains electrolytes, water, proteins, peptides, and glycoproteins. Its components may serve as diagnostic indicators of local and systemic diseases. The aim of the study was to conduct literature review in order to identify the current methods of tear collection. The most commonly used method which was relatively easy to perform and allowed to obtain sufficient tear volume for further chemical and physical analysis was selected through PubMed database search for the following keywords: tear sampling, human tears, chemical analysis of tears, physical tear analysis, animal tear sampling. Final criteria of articles selection were: human tears, tear sample collection, chemical and physical analysis of tears. Time of publication of the articles not older than 1995. The analysis of 70 articles revealed that the most common tear fluid collection methods are Schirmer tear strips and capillary tubes. Thus, we recommend the use of Schirmer strips and microcapillary tubes as the cheapest and easiest methods for sampling of tear fluid for further chemical analysis.

Sign in / Sign up

Export Citation Format

Share Document