scholarly journals A platinum black-modified microelectrode for in situ olanzapine detection in microliter volumes of undiluted serum

2020 ◽  
Vol 127 (2) ◽  
pp. 291-299 ◽  
Author(s):  
Rajendra P. Shukla ◽  
Robert H. Belmaker ◽  
Yuly Bersudsky ◽  
Hadar Ben-Yoav
Keyword(s):  
Liquid Chromatography ◽  
Real Time ◽  
Psychotic Disorders ◽  
Limit Of Detection ◽  
Biological Fluids ◽  
In Situ Monitoring ◽  
Blood Levels ◽  
Platinum Black ◽  
Serum Samples

AbstractOlanzapine is a thienobenzodiazepine compound. It is one of the newer types of antipsychotic drugs used in the treatment of schizophrenia and other psychotic disorders. Several methods have been reported for analyzing olanzapine in its pure form or combined with other drugs and in biological fluids. These methods include high-performance liquid chromatography and liquid chromatography-tandem mass spectroscopy. Although many of the reported methods are accurate and sensitive, they require the use of sophisticated equipment, lack in situ analysis, and require expensive reagents. Moreover, several of these methods are cumbersome, require prolonged sample pretreatment, strict control of pH, and long reaction times. Here we present the development of a miniaturized electrochemical sensor that will enable minimally invasive, real-time, and in situ monitoring of olanzapine levels in microliter volumes of serum samples. For this purpose, we modified a microfabricated microelectrode with a platinum black film to increase the electrocatalytic activity of the microelectrode towards olanzapine oxidation; this improved the overall selectivity and sensitivity of the sensor. We observed in recorded voltammograms the anodic current dose response characteristics in microliter volumes of olanzapine-spiked serum samples that resulted in a limit of detection of 28.6 ± 1.3 nM and a sensitivity of 0.14 ± 0.02 µA/cm2 nM. Importantly, the platinum black-modified microelectrode exhibited a limit of detection that is below the clinical threshold (65–130 nM). Further miniaturizing and integrating such sensors into point-of-care devices provide real-time monitoring of olanzapine blood levels; this will enable treatment teams to receive feedback and administer adjustable olanzapine therapy.

scholarly journals A sample cell for the study of enzyme-induced carbonate precipitation at the grain-scale and its implications for biocementation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jennifer Zehner ◽  
Anja Røyne ◽  
Pawel Sikorski
Keyword(s):  
Real Time ◽  
Laser Scanning Microscopy ◽  
In Situ Monitoring ◽  
Confocal Laser ◽  
Precipitation Process ◽  
Successful Implementation ◽  
Detailed Knowledge ◽  
Carbonate Precipitation ◽  
Sample Cell

AbstractBiocementation is commonly based on microbial-induced carbonate precipitation (MICP) or enzyme-induced carbonate precipitation (EICP), where biomineralization of $$\text {CaCO}_{3}$$ CaCO 3 in a granular medium is used to produce a sustainable, consolidated porous material. The successful implementation of biocementation in large-scale applications requires detailed knowledge about the micro-scale processes of $$\text {CaCO}_{3}$$ CaCO 3 precipitation and grain consolidation. For this purpose, we present a microscopy sample cell that enables real time and in situ observations of the precipitation of $$\text {CaCO}_{3}$$ CaCO 3 in the presence of sand grains and calcite seeds. In this study, the sample cell is used in combination with confocal laser scanning microscopy (CLSM) which allows the monitoring in situ of local pH during the reaction. The sample cell can be disassembled at the end of the experiment, so that the precipitated crystals can be characterized with Raman microspectroscopy and scanning electron microscopy (SEM) without disturbing the sample. The combination of the real time and in situ monitoring of the precipitation process with the possibility to characterize the precipitated crystals without further sample processing, offers a powerful tool for knowledge-based improvements of biocementation.

scholarly journals Sensitive In Situ Monitoring of a Recombinant Bioluminescent Yersinia enterocolitica Reporter Mutant in Real Time on Camembert Cheese

2002 ◽  
Vol 68 (11) ◽  
pp. 5737-5740 ◽  
Author(s):  
Ariel Maoz ◽  
Ralf Mayr ◽  
Geraldine Bresolin ◽  
Klaus Neuhaus ◽  
Kevin P. Francis ◽  
...  
Keyword(s):  
Real Time ◽  
Yersinia Enterocolitica ◽  
Photon Emission ◽  
Photon Counting ◽  
In Situ Monitoring ◽  
Charge Coupled Device ◽  
Reading Frame ◽  
Intensified Charge Coupled Device ◽  
Camembert Cheese

ABSTRACT Bioluminescent mutants of Yersinia enterocolitica were generated by transposon mutagenesis using a promoterless, complete lux operon (luxCDABE) derived from Photorhabdus luminescens, and their production of light in the cheese environment was monitored. Mutant B94, which had the lux cassette inserted into an open reading frame of unknown function was used for direct monitoring of Y. enterocolitica cells on cheeses stored at 10°C by quantifying bioluminescence using a photon-counting, intensified charge-coupled device camera. The detection limit on cheese was 200 CFU/cm2. Bioluminescence of the reporter mutant was significantly regulated by its environment (NaCl, temperature, and cheese), as well as by growth phase, via the promoter the lux operon had acquired upon transposition. At low temperatures, mutant B94 did not exhibit the often-reported decrease of photon emission in older cells. It was not necessary to include either antibiotics or aldehyde in the food matrix in order to gain quantitative, reproducible bioluminescence data. As far as we know, this is the first time a pathogen has been monitored in situ, in real time, in a “real-product” status, and at a low temperature.

Smart Textiles with Biosensing Capabilities

2012 ◽  
Vol 80 ◽  
pp. 129-135 ◽  
Author(s):  
Stéphanie Pasche ◽  
Bastien Schyrr ◽  
Bernard Wenger ◽  
Emmanuel Scolan ◽  
Réal Ischer ◽  
...  
Keyword(s):  
Real Time ◽  
Optical Fibers ◽  
Close Contact ◽  
Biological Fluids ◽  
Wearable Sensors ◽  
Surrounding Medium ◽  
Sol Gel ◽  
The Body ◽  
In Situ Monitoring ◽  
Easy Integration

Real-time, on-body measurement using minimally invasive biosensors opens up new perspectives for diagnosis and disease monitoring. Wearable sensors are placed in close contact with the body, performing analyses in accessible biological fluids (wound exudates, sweat). In this context, a network of biosensing optical fibers woven in textile enables the fabric to measure biological parameters in the surrounding medium. Optical fibers are attractive in view of their flexibility and easy integration for on-body monitoring. Biosensing fibers are obtained by modifying standard optical fibers with a sensitive layer specific to biomarkers. Detection is based on light absorption of the sensing fiber, placing a light source and a detector at both extremities of the fiber. Biosensing optical fibers have been developed for the in situ monitoring of wound healing, measuring pH and the activity of proteases in exudates. Other developments aim at the design of sensing patches based on functionalized, porous sol-gel layers, which can be deposited onto textiles and show optical changes in response to biomarkers. Biosensing textiles present interesting perspectives for innovative healthcare monitoring. Wearable sensors will provide access to new information from the body in real time, to support diagnosis and therapy.

Fast, Real-Time, In Situ Monitoring of Solar Ultraviolet Radiation Using Sunlight-Driven Photoresponsive Liquid Crystals

2018 ◽  
Vol 6 (6) ◽  
pp. 1701337 ◽  
Author(s):  
Jiajun Tian ◽  
Yanrong He ◽  
Juntao Li ◽  
Jie Wei ◽  
Gangqiang Li ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Ultraviolet Radiation ◽  
Real Time ◽  
In Situ Monitoring ◽  
Solar Ultraviolet Radiation ◽  
Solar Ultraviolet

Multifunctional 3D electrode platform for real-time in situ monitoring and stimulation of cardiac tissues

2018 ◽  
Vol 112 ◽  
pp. 149-155 ◽  
Author(s):  
Ning Zhang ◽  
Flurin Stauffer ◽  
Benjamin R. Simona ◽  
Feng Zhang ◽  
Zhao-Ming Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
In Situ Monitoring ◽  
Cardiac Tissues ◽  
3D Electrode ◽  
Stimulation Of

In-Situ Monitoring of Laser Powder Bed Fusion Process Anomalies via a Comprehensive Analysis of Off-Axis Camera Data

2020 ◽  
Author(s):  
Chaitanya Krishna Prasad Vallabh ◽  
Yubo Xiong ◽  
Xiayun Zhao
Keyword(s):  
Real Time ◽  
Network Architecture ◽  
Video Data ◽  
In Situ Monitoring ◽  
Process Efficiency ◽  
Powder Bed Fusion ◽  
Laser Powder Bed Fusion ◽  
Monitoring Method ◽  
Powder Bed

Abstract In-situ monitoring of a Laser Powder-Bed Fusion (LPBF) additive manufacturing process is crucial in enhancing the process efficiency and ensuring the built part integrity. In this work, we present an in-situ monitoring method using an off-axis camera for monitoring layer-wise process anomalies. The in-situ monitoring is performed with a spatial resolution of 512 × 512 pixels, with each pixel representing 250 × 250 μm and a relatively high data acquisition rate of 500 Hz. An experimental study is conducted by using the developed in-situ off-axis method for monitoring the build process for a standard tensile bar. Real-time video data is acquired for each printed layer. Data analytics methods are developed to identify layer-wise anomalies, observe powder bed characteristics, reconstruct 3D part structure, and track the spatter dynamics. A deep neural network architecture is trained using the acquired layer-wise images and tested by images embedded with artificial anomalies. The real-time video data is also used to perform a preliminary spatter analysis along the laser scan path. The developed methodology is aimed to extract as much information as possible from a single set of camera video data. It will provide the AM community with an efficient and capable process monitoring tool for process control and quality assurance while using LPBF to produce high-standard components in industrial (such as, aerospace and biomedical industries) applications.

Comparative, real-time in situ monitoring of galvanic corrosion in Mg-Mg2Ca and Mg-MgZn2 couples in Hank’s solution

2019 ◽  
Vol 161 ◽  
pp. 108185 ◽  
Author(s):  
Yang Liu ◽  
Xiao Liu ◽  
Zechuan Zhang ◽  
Nicholas Farrell ◽  
Dafu Chen ◽  
...  
Keyword(s):  
Real Time ◽  
Galvanic Corrosion ◽  
In Situ Monitoring ◽  
Hank’S Solution

scholarly journals Sensitive Analysis of Idarubicin in Human Urine and Plasma by Liquid Chromatography with Fluorescence Detection: An Application in Drug Monitoring

Molecules ◽  
2020 ◽  
Vol 25 (24) ◽  
pp. 5799
Author(s):  
Olga Maliszewska ◽  
Natalia Treder ◽  
IIona Olędzka ◽  
Piotr Kowalski ◽  
Natalia Miękus ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Biological Fluids ◽  
Internal Standard ◽  
Urine Samples ◽  
Human Plasma And Urine ◽  
Plasma And Urine Samples

A new approach for the sensitive, robust and rapid determination of idarubicin (IDA) in human plasma and urine samples based on liquid chromatography with fluorescence detection (LC-FL) was developed. Satisfactory chromatographic separation of the analyte after solid-phase extraction (SPE) was performed on a Discovery HS C18 analytical column using a mixture of acetonitrile and 0.1% formic acid in water as the mobile phase in isocratic mode. IDA and daunorubicin hydrochloride used as an internal standard (I.S.) were monitored at the excitation and emission wavelengths of 487 and 547 nm, respectively. The method was validated according to the FDA and ICH guidelines. The linearity was confirmed in the range of 0.1–50 ng/mL and 0.25–200 ng/mL, while the limit of detection (LOD) was 0.05 and 0.125 ng/mL in plasma and urine samples, respectively. The developed LC-FL method was successfully applied for drug determinations in human plasma and urine after oral administration of IDA at a dose of 10 mg to a patient with highly advanced alveolar rhabdomyosarcoma (RMA). Moreover, the potential exposure to IDA present in both fluids for healthcare workers and the caregivers of patients has been evaluated. The present LC-FL method can be a useful tool in pharmacokinetic and clinical investigations, in the monitoring of chemotherapy containing IDA, as well as for sensitive and reliable IDA quantitation in biological fluids.

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