scholarly journals Optical pH Detection with U-Shaped Fiber-Optic Probes and Absorption Transducers

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jakub Zajíc ◽  
Lenka Traplová ◽  
Vlastimil Matějec ◽  
Marie Pospíšilová ◽  
Ivo Bartoň
Keyword(s):  
Fiber Optic ◽  
Ph Monitoring ◽  
Porous Silica ◽  
Bromothymol Blue ◽  
Small Sample ◽  
Physiological Processes ◽  
Ph Indicators ◽  
Fiber Optic Probes ◽  
Ph Range

In medicine knowledge of pH values can provide us with information not only about the patients’ status but also about physiological processes in the patient’s body. Measurements of pH in small-sample volumes and online pH monitoring in vivo can be employed to obtain such information. For such measurements we have developed and investigated U-shaped fiber-optic probes with immobilized pH indicators in this paper. U-shaped probes with a diameter of about 2 mm were prepared. Three different pH indicators, methyl red, methyl orange, and bromothymol blue, were immobilized in two types of matrices, namely, porous silica (PS) and ethylcellulose (EC), and applied on the U-shaped probes. Changes in spectra of transmitted power were measured and calibration curves were determined from these spectra. It has been found that a working pH range of prepared probes was from 3.1 to 7.6. The maximum sensitivity was about 0.1 1/pH unit. Effects of structural relaxations of detection layers and indicator leaching observed in experiments are discussed.

scholarly journals Transmitted light pH optode for small sample volumes

2017 ◽  
Vol 6 (2) ◽  
pp. 351-359 ◽  
Author(s):  
Christian Rogge ◽  
Steffen Zinn ◽  
Paolo Prosposito ◽  
Roberto Francini ◽  
Andreas H. Foitzik
Keyword(s):  
Color Change ◽  
Ph Value ◽  
Ph Monitoring ◽  
Low Cost ◽  
Small Sample ◽  
Phenol Red ◽  
Color Sensor ◽  
Ph Indicators ◽  
Hsv Color Model ◽  
Ph Range

Abstract. An innovative concept of a low-cost pH optode with working volumes of less than 150 µL is presented. The pH monitoring is based on the color changing effect of pH indicators. The optode includes an RGB color sensor patch TCS34725 from Adafruit, a controllable LED and reactor slides and is addressed by a self-written LabVIEW© software. Utilizing the hue value of the HSV color model, it is possible to analyze the color change of the indicator and estimate the pH value of the analyzed samples by exploiting sigmoidal fit models. Measurements carried out with phenol red and DMEM (Dulbecco's Modified Eagle's Medium) reported a standard error of calibration in the physiologic pH range (6.5–7.5) of ±0.04 pH units.

scholarly journals Modelling, Design and Validation of Spatially Resolved Reflectance Based Fiber Optic Probe for Epithelial Precancer Diagnostics

2020 ◽  
Vol 10 (24) ◽  
pp. 8836
Author(s):  
Pankaj Singh ◽  
Prabodh Pandey ◽  
Shivam Shukla ◽  
Naren Naik ◽  
Asima Pradhan
Keyword(s):  
Fiber Optic ◽  
Numerical Study ◽  
Fiber Optic Probe ◽  
Scattering Coefficients ◽  
Spatially Resolved ◽  
Fiber Optic Probes ◽  
Diagnosis Of Cancer ◽  
Optic Probe ◽  
In Vivo Diagnosis

Fiber-optic probes are imperative for in-vivo diagnosis of cancer. Depending on the access to a diseased organ and the mutations one aims to sense, the probe designs vary. We carry out a detailed numerical study of the efficacy of the common probe geometries for epithelial cancer characterization based on spatially resolved reflectance data. As per the outcomes of this comparative study, a probe has been manufactured and using Monte Carlo look up table based inversion scheme, the absorption and scattering coefficients of the epithelium mimicking top layer have been recovered from noisy synthetic as well as experimental data.

Study of Fiber-Optic Probes for in vivo Medical Raman Spectroscopy

1999 ◽  
Vol 53 (6) ◽  
pp. 619-627 ◽  
Author(s):  
Martin G. Shim ◽  
Brian C. Wilson ◽  
Eric Marple ◽  
Michael Wach
Keyword(s):  
Raman Spectroscopy ◽  
Fiber Optic ◽  
Fiber Optic Probes

Fiber-Optic Probes for in Vivo Raman Spectroscopy in the High-Wavenumber Region

2005 ◽  
Vol 77 (20) ◽  
pp. 6747-6752 ◽  
Author(s):  
Luís F. Santos ◽  
Rolf Wolthuis ◽  
S. Koljenović ◽  
Rui M. Almeida ◽  
Gerwin J. Puppels
Keyword(s):  
Raman Spectroscopy ◽  
Fiber Optic ◽  
Fiber Optic Probes ◽  
In Vivo Raman Spectroscopy ◽  
Wavenumber Region

Radio-opaque isotropic fiber optic probes for in vivo photodynamic therapy dosimetry

1994 ◽  
Author(s):  
Emma J. Hudson ◽  
Mark R. Stringer ◽  
Hugo J. van Staveren ◽  
Michael A. Smith
Keyword(s):  
Photodynamic Therapy ◽  
Fiber Optic ◽  
Fiber Optic Probes

Evaluation of fiber optic probes for in-vivo Raman spectroscopy

1998 ◽  
Author(s):  
Martin G. Shim ◽  
Brian C. Wilson ◽  
Eric Marple ◽  
Michael L. Wach
Keyword(s):  
Raman Spectroscopy ◽  
Fiber Optic ◽  
Fiber Optic Probes ◽  
In Vivo Raman Spectroscopy

Fiber-optic probes for in vivo depth-resolved neuron-activity mapping

2010 ◽  
Vol 3 (10-11) ◽  
pp. 660-669 ◽  
Author(s):  
Lyubov V. Doronina-Amitonova ◽  
Il'ya V. Fedotov ◽  
Olga I. Ivashkina ◽  
Marina A. Zots ◽  
Andrei B. Fedotov ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Neuron Activity ◽  
Fiber Optic Probes

Probing the ultrastructure of the mitotic and meiotic spindle in eggs: An expeditious approach based on semi-thin (0.25 μm) serial sections

1983 ◽  
Vol 41 ◽  
pp. 552-555
Author(s):  
Conly L. Rieder ◽  
S. Bowser ◽  
R. Nowogrodzki ◽  
K. Ross ◽  
G. Sluder
Keyword(s):  
Small Sample Size ◽  
Small Sample ◽  
Meiotic Spindle ◽  
Serial Sections ◽  
Mitotic Apparatus ◽  
Thin Sections ◽  
Cell Cycles ◽  
Ultrastructural Studies

Eggs have long been a favorite material for studying the mechanism of karyokinesis in-vivo and in-vitro. They can be obtained in great numbers and, when fertilized, divide synchronously over many cell cycles. However, they are not considered to be a practical system for ultrastructural studies on the mitotic apparatus (MA) for several reasons, the most obvious of which is that sectioning them is a formidable task: over 1000 ultra-thin sections need to be cut from a single 80-100 μm diameter egg and of these sections only a small percentage will contain the area or structure of interest. Thus it is difficult and time consuming to obtain reliable ultrastructural data concerning the MA of eggs; and when it is obtained it is necessarily based on a small sample size.We have recently developed a procedure which will facilitate many studies concerned with the ultrastructure of the MA in eggs. It is based on the availability of biological HVEM's and on the observation that 0.25 μm thick serial sections can be screened at high resolution for content (after mounting on slot grids and staining with uranyl and lead) by phase contrast light microscopy (LM; Figs 1-2).

Platelet Microtubules in Clot Structure Formation and Contractile Force Generation: Investigation of a Controversy

1986 ◽  
Vol 56 (01) ◽  
pp. 023-027 ◽  
Author(s):  
C J Jen ◽  
L V McIntire
Keyword(s):  
Network Formation ◽  
Contractile Force ◽  
Second Phase ◽  
Clot Retraction ◽  
Forming Process ◽  
Microtubule Organization ◽  
Physiological Processes ◽  
Fibrin Network ◽  
Two Parameters

SummaryWhether platelet microtubules are involved in clot retraction/ contraction has been controversial. To address this question we have simultaneously measured two clotting parameters, clot structural rigidity and isometric contractile force, using a rheological technique. For recalcified PRP clots these two parameters began rising together at about 15 min after CaCl2 addition. In the concentration range affecting microtubule organization in platelets, colchicine, vinca alkaloids and taxol demonstrated insignificant effects on both clotting parameters of a recalcified PRP clot. For PRP clots induced by adding small amounts of exogenous thrombin, the kinetic curves of clot rigidity were biphasic and without a lag time. The first phase corresponded to a platelet-independent network forming process, while the second phase corresponded to a platelet-dependent process. These PRP clots began generating contractile force at the onset of the second phase. For both rigidity and force parameters, only the second phase of clotting kinetics was retarded by microtubule affecting reagents. When PRP samples were clotted by adding a mixture of CaCl2 and thrombin, the second phase clotting was accelerated and became superimposed on the first phase. The inhibitory effects of micro tubule affecting reagents became less pronounced. Thrombin clotting of a two-component system (washed platelets/ purified fibrinogen) was also biphasic, with the second phase being microtubule-dependent. In conclusion, platelet microtubules are important in PRP clotted with low concentrations of thrombin, during which fibrin network formation precedes platelet-fibrin interactions. On the other hand they are unimportant if a PRP clot is induced by recalcification, during which the fibrin network is constructed in the presence of platelet-fibrin interactions. The latter is likely to be more analogous to physiological processes in vivo.

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