Optical control of the interface between gold surface and blood cell samples

2021 ◽  
Vol 56 ◽  
pp. 134-155
Author(s):  
Yu. M. Shirshov ◽  

The optical properties of blood (spectra of the extinction coefficient, k, refractive index, n, etc.) carry important diagnostic information and are usually monitored using bulk samples. In this work, attention is drawn to the interface between the blood volume and the surface of glass or thin gold films on it, where the refractive index may differ from the bulk one. We draw attention to the relationship between two effects – SPR and TIR. It is shown that if the named effects are measured for two different external media 0 and 1 with different refractive indices, then the values of the angles SPR and TIR will be linearly related by the empirical formula SPR1=SPR0+TIR1- TIR0)*K, where the coefficient K depends on the thickness of the transition layer di between the surface and the volume of the liquid medium (suspension). Numerical calculation of K (di) for gold films shows that K = 1.6 at di = 0 and monotonically decreases to 0.01 with an increase in di to 300 nm (and further to 0). Measurement of the angular dependences of reflection, R(), on (1) 100% hematocrit blood samples, (2) hemolyzed samples and (3) washed erythrocytes with dilutions with a buffer solution. It was shown that all samples exhibit a minimum SPR, but the TIR angle can be measured only for blood samples with destroyed membranes (hemolyzed), buffer solution and plasma. The n-value for hemolyzed blood is 1.3505, which is indicative of a low hemoglobin content in the sample. At the same time, di for a sample of 100% hematocrit was 60-105 nm, which indicates a strong deformation of erythrocytes in the form of polyhedrocytes and their dense packing after centrifugation. Washing the cells with a buffer increases di to 280 nm and more and practically eliminates blood cells from the SPR sensitivity region. The reason for this may be that in the blood of 100% hematocrit, erythrocytes are in the form of polyhedrocytes tightly adhering to the gold surface, while as a result of washing and diluting with a buffer solution, the cells relax back into discocytes. As a result, the containing hemoglobin erythrocyte cytoplasm moves away from the surface at a distance di> 300 nm into the suspension volume and leaves the area of the enhanced plasmon-polariton field.

1954 ◽  
Vol 35 (2) ◽  
pp. 56-59 ◽  
Author(s):  
D. L. Randall

This study was made to investigate the relationship of surface meteorological data and corresponding surface refractive indices to radio field strengths in the FM frequency band. For meteorological observations during which the wind speeds were equal to or greater than 10 mph, and when fronts, low overcast clouds (less than 5000 ft), rain, thunderstorms and fogs were excluded, a 0.70 correlation coefficient was found between hourly surface refractive index and hourly median field strength over a Washington-Richmond path at a frequency of 96.3 Mc.


2017 ◽  
Vol 38 (2) ◽  
Author(s):  
Ruei-Chang Lu ◽  
Keh-Yi Lee

AbstractIn this work, the authors propose a modified type of multi-stage directional couplers and combine it with a wavelength-tunable laser to measure the refractive index of an undetermined biochemical liquid/solution. Tuning the wavelength of the laser incident on the modified multi-stage directional couplers, the relationship between the wavelength corresponding to the maximal output optical power and the refractive index of the unknown fluid has been obtained.


Clay Minerals ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 97-103 ◽  
Author(s):  
M. Heuser ◽  
P. Andrieux ◽  
S. Petit ◽  
H. Stanjek

AbstractStructural iron in smectites correlates with the cell edge length b and increases the refractive index. The cell edge length b is usually obtained from the position of the (060) reflection, but in this work we show that such b values differ from the values obtained from Rietveld fits because contributions from (hkl) reflections shift the position of the (060) reflection. The correlation between Fe and cell edge length b was significant (r2 > 0.99); the relationship is b [Å] = 8.9977(0.0035) + 0.1117(0.0032) × Fetot. Furthermore, we present for the first time measurements of the refractive index n of Fe-bearing smectites, applying a recently published turbidity method (Weidler & Friedrich, 2007). The refractive index correlates both with structural iron (r2 = 0.64) and with b (r2 = 0.94).


1960 ◽  
Vol 6 (1) ◽  
pp. 89-105 ◽  
Author(s):  
S. J. Webb

The relationship between cellular water and the death of air-borne cells, and the effect of added substances on these relationships, has been studied. The rate of death of air-stored cells has been correlated with the amount of water bonded to the cellular proteins. Refractive indices of cells, measured by light scatter and interferometry, have suggested that cells suspended in solutions of various compounds contain less water. With the exception of urea, the more able a compound is in displacing water, the less its protectiveness to air-borne cells. Inositol produced the smallest change in the water content and refractive index of cells. This is taken to indicate that, in the absence of water, this compound can form hydrogen bonds with cellular protein which are reversible with water. There appears also to be some relationship between the Gram stain reaction and aerosol stability of the cells. Ribonuclease and lysozyme treatment of air-stable cells rendered them air sensitive, whereas resistance to some antibiotics, and suspension in some antibiotics, afforded stability to air-sensitive cells. It is suggested that the site of damage is the cellular "membranes" which break down on desiccation and result in a loss of differentiation within the cell.


Author(s):  
Walter C. McCrone

An excellent chapter on this subject by V.D. Fréchette appeared in a book edited by L.L. Hench and R.W. Gould in 1971 (1). That chapter with the references cited there provides a very complete coverage of the subject. I will add a more complete coverage of an important polarized light microscope (PLM) technique developed more recently (2). Dispersion staining is based on refractive index and its variation with wavelength (dispersion of index). A particle of, say almandite, a garnet, has refractive indices of nF = 1.789 nm, nD = 1.780 nm and nC = 1.775 nm. A Cargille refractive index liquid having nD = 1.780 nm will have nF = 1.810 and nC = 1.768 nm. Almandite grains will disappear in that liquid when observed with a beam of 589 nm light (D-line), but it will have a lower refractive index than that liquid with 486 nm light (F-line), and a higher index than that liquid with 656 nm light (C-line).


1979 ◽  
Vol 44 (7) ◽  
pp. 2064-2078 ◽  
Author(s):  
Blahoslav Sedláček ◽  
Břetislav Verner ◽  
Miroslav Bárta ◽  
Karel Zimmermann

Basic scattering functions were used in a novel calculation of the turbidity ratios for particles having the relative refractive index m = 1.001, 1.005 (0.005) 1.315 and the size α = 0.05 (0.05) 6.00 (0.10) 15.00 (0.50) 70.00 (1.00) 100, where α = πL/λ, L is the diameter of the spherical particle, λ = Λ/μ1 is the wavelength of light in a medium with the refractive index μ1 and Λ is the wavelength of light in vacuo. The data are tabulated for the wavelength λ = 546.1/μw = 409.357 nm, where μw is the refractive index of water. A procedure has been suggested how to extend the applicability of Tables to various refractive indices of the medium and to various turbidity ratios τa/τb obtained with the individual pairs of wavelengths λa and λb. The selection of these pairs is bound to the sequence condition λa = λ0χa and λb = λ0χb, in which b-a = δ = 1, 2, 3; a = -2, -1, 0, 1, 2, ..., b = a + δ = -1, 0, 1, 2, ...; λ0 = λa=0 = 326.675 nm; χ = 546.1 : 435.8 = 1.2531 is the quotient of the given sequence.


Animals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 926
Author(s):  
Daniela M. Meléndez ◽  
Sonia Marti ◽  
Luigi Faucitano ◽  
Derek B. Haley ◽  
Timothy D. Schwinghamer ◽  
...  

Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer and a traditional lactate assay colorimetric kit. Blood samples were collected by venipuncture from 96 steers (Black or Red Angus × Hereford/Simmental and Black or Red Angus × Charolais; 247 ± 38.2 kg BW) prior to loading (LO1) and after 36 h of transport, and prior to reloading and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in the colorimetric analysis. Pearson correlations were calculated to assess the strength of the relationship between the experimental methods for the quantification of L-lactate concentrations. The magnitude and direction of the correlation, and the level of statistical significance varied over the observed time points, ranging from r = −0.03 (p = 0.75; LO1) to r = 0.75 (p < 0.0001; d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, p < 0.0001). Based on the low magnitude of the correlation due to variability across sampling time points in this study, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay (considered the gold standard) for measuring L-lactate in transported cattle.


2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 296-297
Author(s):  
Daniela M Meléndez ◽  
Sonia Marti ◽  
Luigi Faucitano ◽  
Derek B Haley ◽  
Timothy D Schwinghamer ◽  
...  

Abstract Blood metabolites are used to assess a variety of animal conditions for veterinary diagnosis and research. Concentration of metabolites in blood can be measured using a commercially-available lab-based assay or in real-time using a handheld device developed to be more time- and cost-effective than the lab-based method. Lactate is a product of anaerobic glycolysis, used in animal research as an indicator of muscle fatigue. Therefore, it has been used as an indicator of cattle response to long distance transportation. The aim of this study was to assess the relationship of L-lactate concentrations measured using a Lactate Scout+ analyzer (Lactate Scout, EFK Diagnostics, Barleben, Germany) and a lactate assay colorimetric kit (Lactate Assay Kit, Cell Biolabs Inc., San Diego, CA). Blood samples were collected by venipuncture from 96 steers (245 ± 35.7 kg BW) prior to (L1) and after 36 h, and prior to and after an additional 4 h of road transportation, and on d 1, 2, 3, 5, 14, and 28 after transport. The Lactate Scout+ analyzer strip was dipped in blood at the time of sampling, while blood samples were collected into sodium fluoride tubes for use in colorimetric analysis. Pearson correlations were calculated to determine the relationship between the experimental methods for the quantification of L-lactate concentrations. The strengths and levels of statistical significance of the correlation varied over the observed time points, r = -0.03, P = 0.75 (L1) to r = 0.75, P = &lt; 0.0001 (d 3). The correlation for the pooled data was weak but statistically significant (r = 0.33, P &lt; 0.001). Based on the experimental results, the Lactate Scout+ analyzer is not a suitable alternative to a lab-based assay for measuring L-lactate in transported cattle, due to variability across sampling time points and weak correlation with the traditional enzymatic method.


2018 ◽  
Vol 879 ◽  
pp. 227-233
Author(s):  
Weeratouch Pongruengkiat ◽  
Thitika Jungpanich ◽  
Kodchakorn Ittipornnuson ◽  
Suejit Pechprasarn ◽  
Naphat Albutt

Refractive index and Abbe number are major physical properties of optical materials including glasses and transparent polymers. Refractive index is, in fact, not a constant number and is varied as a function of optical wavelength. The full refractive index spectrum can be obtained using a spectrometer. However, for optical component designers, three refractive indices at the wavelengths of 486.1 nm, 589.3 nm and 656.3 nm are usually sufficient for most of the design tasks, since the rest of the spectrum can be predicted by mathematical models and interpolation. In this paper, we propose a simple optical instrumental setup that determines the refractive indices at three wavelengths and the Abbe number of solid and liquid materials.


2016 ◽  
Vol 122 (4) ◽  
Author(s):  
Sebastian Goetz ◽  
Gary Razinskas ◽  
Enno Krauss ◽  
Christian Dreher ◽  
Matthias Wurdack ◽  
...  

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