scholarly journals Stabilized sensing of heparin in whole blood using the ‘gate effect’ of heparin-imprinted polymer grafted onto an electrode

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Yasuo Yoshimi ◽  
Ryo Inaba ◽  
Takaya Ogawa ◽  
Waka Yoshino ◽  
Masaru Inoue ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Whole Blood ◽  
Physiological Saline ◽  
Current Intensity ◽  
Imprinted Polymer ◽  
Heparin Concentration ◽  
Ito Electrode ◽  
Gate Effect ◽  
The Relationship ◽  
Potential Tool

AbstractA real-time heparin monitor is required to optimize the dosage of heparin and its antidote, protamine sulfate, during extracorporeal circulation procedures. The gate effect of molecularly imprinted polymer (MIP) is a potential tool for the rapid and selective sensing of heparin. We here present a method to stabilize the measurement of heparin concentration in whole blood using an MIP-grafted electrode. An initiator of radical polymerization, the diethyldithiocarbamicbenzyl group, was introduced onto the surface of an indium-tin oxide (ITO) electrode. Heparin sodium, methacryloxethyltrimethoxysilane, and acrylamide were dissolved in water, and methylenebisacrylamide was dissolved in dimethylformamide. A mixture of the two solutions was introduced into the 50 μm gap between the surfaces of a quartz crystal plate and the treated ITO electrode. Ultraviolet light was irradiated onto the surface of the ITO to graft the copolymer of the monomers, then the ITO was washed with a 1 M sodium chloride aqueous solution to remove the heparin template and obtain the MIP-grafted electrode. Cyclic voltammetry was performed with the MIP-grafted electrode in physiological saline or bovine whole blood containing 0-8 units/ mL heparin and 5 mM ferrocyanide as a redox marker, and the relationship between the current intensity and the heparin concentration was analyzed. The current intensity decreased as the heparin concentration in either saline or whole blood increased, and the sensitivity of the electrode to heparin in blood was approximately 52% of its sensitivity to heparin in saline. The grafted-electrode was washed with a protease-containing detergent (Sterizyme® S, Maruishi Pharmaceutical) between measurements in blood. The heparin-sensitivity of the washed electrode in blood was 77% of that in saline. No sensitivity to chondroitin sulfate C was observed but sensitivity to low molecular weight heparin was demonstrated. We thus conclude that selective and stable sensing of heparin can be achieved using an electrode grafted with heparinimprinted polymer.

scholarly journals Reagentless Sensing of Vancomycin Using an Indium Tin Oxide Electrode Grafted with Molecularly Imprinted Polymer including Ferrocenyl Group

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8338
Author(s):  
Haruto Eguchi ◽  
Akihiko Hatano ◽  
Yasuo Yoshimi
Keyword(s):  
Tin Oxide ◽  
Molecularly Imprinted Polymer ◽  
Indium Tin Oxide ◽  
Dynamic Range ◽  
Therapeutic Drug ◽  
Background Current ◽  
Imprinted Polymer ◽  
High Background ◽  
Molecularly Imprinted ◽  
Ito Electrode

Vancomycin (VCM) is a first-line antimicrobial agent against methicillin-resistant Staphylococcus aureus, a cause of nosocomial infections. Therapeutic drug monitoring is strongly recommended for VCM-based chemotherapy. The authors attempted to develop a simple VCM sensor based on molecularly imprinted polymer (MIP), which can be used with simple operations. Methacrylic acid (MAA), acrylamide, methylenebisacrylamide, and allylamine carboxypropionate-3-ferrocene (ACPF) were copolymerized in the presence of VCM and grafted from the surface of indium-tin oxide (ITO) to obtain MIP-coated electrodes. The MIP-grafted ITO electrode was used for differential pulse voltammetry (DPV) measurements in a buffer solution containing VCM or whole bovine blood. The obtained current depends on the VCM concentration with high linearity. The dynamic range covered the therapeutic range (20–40 μg/mL) of the VCM but was almost insensitive to teicoplanin, which has a similar structure to VCM. The ITO electrodes grafted by the same procedure except for omitting either VCM or APCF were not sensitive to VCM. The sensitivity of the MIP electrodes to VCM in whole blood and buffered saline, but the background current in blood was higher than that in saline. This high background current was also seen in the deproteinized plasma. Thus, the current is probably originated from the oxidation of low molecular weight reducing agents in the blood. The MIP-grafted ITO electrode using ACPF as a functional monomer would be a promising highly selective sensor for real-time monitoring of VCM with proper correction of the background current.

Monitoring Anticoagulant Therapy by Activated Partial Thromboplastin Time: Hirudin Assessment

1994 ◽  
Vol 72 (05) ◽  
pp. 685-692 ◽  
Author(s):  
Michael T Nurmohamed ◽  
René J Berckmans ◽  
Willy M Morriën-Salomons ◽  
Fenny Berends ◽  
Daan W Hommes ◽  
...  
Keyword(s):  
Whole Blood ◽  
Partial Thromboplastin Time ◽  
Ex Vivo ◽  
Fold Increase ◽  
Heparin Therapy ◽  
Activated Partial Thromboplastin Time ◽  
Recombinant Hirudin ◽  
Interindividual Differences ◽  
The Relationship

SummaryBackground. Recombinant hirudin (RH) is a new anticoagulant for prophylaxis and treatment of venous and arterial thrombosis. To which extent the activated partial thromboplastin time (APTT) is suitable for monitoring of RH has not been properly evaluated. Recently, a capillary whole blood device was developed for bed-side monitoring of the APTT and it was demonstrated that this device was suitable to monitor heparin therapy. However, monitoring of RH was not evaluated.Study Objectives. To evaluate in vitro and ex vivo the responsiveness and reproducibility for hirudin monitoring of the whole blood monitor and of plasma APTT assays, which were performed with several reagents and two conventional coagulometers.Results. Large interindividual differences in hirudin responsiveness were noted in both the in vitro and the ex vivo experiments. The relationship between the APTT, expressed as clotting time or ratio of initial and prolonged APTT, and the hirudin concentration was nonlinear. A 1.5-fold increase of the clotting times was obtained at 150-200 ng/ml plasma. However, only a 2-fold increase was obtained at hirudin levels varying from 300 ng to more than 750 ng RH/ml plasma regardless of the assays. The relationship linearized upon logarithmic conversion of the ratio and the hirudin concentration. Disregarding the interindividual differences, and presuming full linearity of the relationship, all combinations were equally responsive to hirudin.Conclusions. All assays were equally responsive to hirudin. Levels up to 300 ng/ml plasma can be reliably estimated with each assay. The manual device may be preferable in situations where rapid availability of test results is necessary.

The relationship between chemical elements in soil and whole blood, and fluorosis induced by coal-fired pollution

2013 ◽  
Vol 186 (4) ◽  
pp. 2081-2088 ◽  
Author(s):  
Hao Wang ◽  
Lihong Mu ◽  
Miao Jiang ◽  
Yingxiong Wang ◽  
Wei Yan ◽  
...  
Keyword(s):  
Whole Blood ◽  
Chemical Elements ◽  
The Relationship

scholarly journals Performance of GaN-Based LEDs with Nanopatterned Indium Tin Oxide Electrode

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zhanxu Chen ◽  
Wenjie Liu ◽  
Wei Wan ◽  
Gengyan Chen ◽  
Yongzhu Chen ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Ohmic Contacts ◽  
Three Dimensional ◽  
Light Output ◽  
Light Extraction Efficiency ◽  
Experimental Result ◽  
Indium Tin Oxide Electrode ◽  
Light Emitting ◽  
Ito Electrode

The indium tin oxide (ITO) has been widely applied in light emitting diodes (LEDs) as the transparent current spreading layer. In this work, the performance of GaN-based blue light LEDs with nanopatterned ITO electrode is investigated. Periodic nanopillar ITO arrays are fabricated by inductive coupled plasma etching with the mask of polystyrene nanosphere. The light extraction efficiency (LEE) of LEDs can be improved by nanopatterned ITO ohmic contacts. The light output intensity of the fabricated LEDs with nanopatterned ITO electrode is 17% higher than that of the conventional LEDs at an injection current of 100 mA. Three-dimensional finite difference time domain simulation matches well with the experimental result. This method may serve as a practical approach to improving the LEE of the LEDs.

scholarly journals Fabrication of New Liquid Crystal Device Using Layer-by-Layer Thin Film Process

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 108 ◽  
Author(s):  
Gitae Moon ◽  
Wonjun Jang ◽  
Intae Son ◽  
Hyun Cho ◽  
Yong Park ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Indium Tin Oxide ◽  
Film Growth ◽  
Mechanical Stability ◽  
Liquid Crystal Display ◽  
Layer By Layer ◽  
Transparent Electrodes ◽  
Ito Electrode ◽  
Display Performance ◽  
Layer Thin Film

Indium tin oxide (ITO) transparent electrodes are troubled with high cost and poor mechanical stability. In this study, layer-by-layer (LBL)-processed thin films with single-walled carbon nanotubes (SWNTs) exhibited high transparency and electrical conductivity as a candidate for ITO replacement. The repetitive deposition of polycations and stabilized SWNTs with a negative surfactant exhibits sufficiently linear film growth and high optoelectronic performance to be used as transparent electrodes for vertically aligned (VA) liquid crystal display (LCD) cells. The LC molecules were uniformly aligned on the all of the prepared LBL electrodes. VA LCD cells with SWNT LBL electrodes exhibited voltage-transmittance (V-T) characteristics similar to those with the conventional ITO electrodes. Although the response speeds were slower than the LCD cell with the ITO electrode, as the SWNT layers increased, the display performance was closer to the LCD cells with conventional ITO electrode. This work demonstrated the good optoelectronic performance and alignment compatibility with LC molecules of the SWNT LBL assemblies, which are potential alternatives to ITO films as transparent electrodes for LCDs.

Characterization of electrocatalytic proton reduction and surface adsorption of platinum nanoparticles supported by a polymeric stabilizer on an ITO electrode

2022 ◽  
Author(s):  
Yuta Tsubonouchi ◽  
Masashi Kajita ◽  
Taichi Hayasaka ◽  
Hamada S. A. Mandour ◽  
Mohamed R Berber ◽  
...  
Keyword(s):  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Platinum Nanoparticles ◽  
Colloidal Solution ◽  
Surface Adsorption ◽  
Chemical Adsorption ◽  
Proton Reduction ◽  
Ito Electrode ◽  
Polymeric Stabilizer

Platinum nanoparticles (PAA-Pt) stabilized by polyacrylic acid (PAA) of a polymeric stabilizer were adsorbed on an indium tin oxide (ITO) surface from their colloidal solution due to the chemical adsorption...

Longitudinal Observations of the Relationship Between Free Erythrocyte Porphyrins and Whole Blood Lead

PEDIATRICS ◽  
1976 ◽  
Vol 57 (1) ◽  
pp. 54-59
Author(s):  
J. Routt Reigart ◽  
Norris H. Whitlock
Keyword(s):  
Whole Blood ◽  
Blood Lead ◽  
Elevated Blood ◽  
Long Term Follow Up ◽  
Short And Long Term ◽  
First Contact ◽  
The Relationship ◽  
Clinical Category

Short- and long-term comparison of the variations with time of whole blood lead and free erythrocyte porphyrins (FEP) suggests that changes in FEP are slow and predictable whereas blood lead changes are quite unpredictable. However, when FEP suggests a different clinical category from blood lead, the blood lead is likely to change in the direction predicted by the FEP. Comparison of FEP to blood lead at first contact in 349 children with mild elevation of blood lead reliably predicted which children would still have elevated blood lead six weeks later and which would fall or be normal. The observation of long-term follow-up in four groups of children with various combinations of FEP and blood lead indicated that the follow-up blood lead could be predicted to change in the direction indicated by the FEP measurement. The implications for screening for lead poisoning are discussed.

scholarly journals Dyslipidemia and Meibomian Gland Dysfunction: Utility of Lipidomics and Experimental Prospects with a Diet-Induced Obesity Mouse Model

2019 ◽  
Vol 20 (14) ◽  
pp. 3505 ◽  
Author(s):  
Eugene A. Osae ◽  
Philipp Steven ◽  
Rachel Redfern ◽  
Samuel Hanlon ◽  
C. Wayne Smith ◽  
...  
Keyword(s):  
Experimental Approach ◽  
Current Knowledge ◽  
Meibomian Gland ◽  
Conclusive Evidence ◽  
Blood Cholesterol ◽  
Meibomian Gland Dysfunction ◽  
Suitable Model ◽  
Diet Induced Obesity ◽  
The Relationship ◽  
Potential Tool

Meibomian gland dysfunction (MGD) is the leading cause of dry eye disease and loss of ocular surface homeostasis. Increasingly, several observational clinical studies suggest that dyslipidemia (elevated blood cholesterol, triglyceride or lipoprotein levels) can initiate the development of MGD. However, conclusive evidence is lacking, and an experimental approach using a suitable model is necessary to interrogate the relationship between dyslipidemia and MGD. This systematic review discusses current knowledge on the associations between dyslipidemia and MGD. We briefly introduce a diet-induced obesity model where mice develop dyslipidemia, which can serve as a potential tool for investigating the effects of dyslipidemia on the meibomian gland. Finally, the utility of lipidomics to examine the link between dyslipidemia and MGD is considered.

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