Class-selective drug detection: fluorescently-labeled calmodulin as the biorecognition element for phenothiazines and tricyclic antidepressants

A small-scale, homogeneous, rapid sensing system for phenothiazines and tricyclic antidepressants (TCAs) has been developed by employing fluorescently labeled mutant calmodulin (CaM) as the recognition element. A calmodulin mutant containing a unique cysteine residue at position 109 on the protein was expressed in Escherichia coli. Following purification, the environment-sensitive, thiol-specific fluorophores N-[2-(1-maleimidyl)ethyl]-7-(diethylamino)coumarin-3-carboxamide (MDCC), 6-acryloyl-2-dimethylaminonaphthalene (acrylodan), and 4-[N-(2-(iodoacetoxy)ethyl)-N-methylamino]-7-nitrobenz-2-oxa-1,3-diazole (IANBD ester) were coupled to the C109 site of the mutant protein. The response of labeled CaM in the presence of calcium to increasing concentrations of chlorpromazine hydrochloride (CPZ), as well as other phenothiazines and structurally related antipsychotics and antidepressants, was investigated. Fluorescence measurements were performed on benchtop and microtiter plate fluorometers. The responses were characterized as a change in the signal intensity of the labeled protein upon ligand binding, and the stability of the system was monitored over a nine-month period. The assay showed specificity for the phenothiazine and TCA classes of drugs, with limits of detection in the micromolar range. Selectivity studies indicated negligible response of the biosensing system to structurally unrelated compounds. This work represents a proof-of-concept assay for rapid, homogeneous detection of drugs employing binding proteins as the biorecognition element

<title>Genetically designed biosensing systems for high-throughput screening of pharmaceuticals, clinical diagnostics, and environmental monitoring</title>

The genetically-modified binding proteins calmodulin, the phosphate binding protein, the sulfate binding protein, and the galactose/glucose binding protein have been successfully employed as biosensing elements for the detection of phenothiazines, phosphate, sulfate, and glucose, respectively. Mutant proteins containing unique cysteine residues were utilized in the site-specific labeling of environment-sensitive fluorescent probes. Changes in the environment of the probes upon ligand-induced conformational changes of the proteins result in changes in fluorescence intensity

Black Education in the Wake of COVID-19 and Systemic Racism: Toward a Theory of Change and Action

This report presents findings from a research study the Black Education Research Collective (BERC) conducted to better understand how the COVID-19 pandemic and systemic racism have impacted Black education from the perspectives of Black parents, teachers, students, educators, and community leaders. Findings underscored the historical and systemic nature of trauma in Black communities as a result of racism in U.S. institutions, including schools and school systems. Participants expressed concern over the fact that schools are ill-equipped to meet the social, emotional, and academic needs of their children and that COVID-19 and increasing racial violence have revealed further their lack of capacity or willingness to meet the educational needs of Black students or expectations of Black parents

Biosensing on the CD Microfluidic Platform with Genetically Engineered Proteins

The current Si/polymeric medical diagnostic sensors that are on the market only feature a one-point calibration system [1]. Such a measurement results in less accurate sensing and more in-factory sensor rejection. The two-point calibration fluidic method introduced here will alleviate some of the shortcomings of such current miniature analytical systems. Our fluidic platform is a disposable, multi-purpose micro analytical laboratory on a compact disc (CD) [2, 3]. This system is based on the centrifugal force, in which fluidic flow can be controlled by the spinning rate of the CD and thus a whole range of fluidic functions including valving, mixing, metering, splitting, and separation can be implemented. Furthermore, optical detection such as absorption and fluorescence can be incorporated into the CD control unit to obtain signals from pre-specified positions on the disc. For such optical detection schemes, it is important that the CD polymer provides no interference (e.g., fluorescence/absorbance background) in the spectral region of the molecular probe employed in the assay. Herein, the spectral characteristics of three prospective CD polymers are also investigated. In addition, studies regarding the compatibility of using these polymers in conjunction with biological reagents were performed

Analysis of factors causing runway excursion incidents and accidents

A runway excursion occurs when a departing aircraft fails to become airborne or successfully rejects the take off before reaching the end of the designated runway or when upon landing, it is unable to stop before the end of the designated runway is reached. It is a veer off or overrun from the runway surface. In most cases, authorities issue recommendations to the pilots to be followed during landing and takeoff to avoid it from happening in future. However, the recommendations are in terms of following appropriate procedures that may not be adequate due to technical issues.Students of AVI 350 (Advanced Aerodynamics) course in Spring 2021 semester have collected data for runway excursion occurrence in USA since 2015 and analyzed it. Their analysis brings out the correlation among various factors causing it such as type of aircraft, runway condition, crosswind, aquaplaning, weather conditions, pilot stress level, communication between Air Traffic Control and pilot etc. The value of this research lies in identifying the technical remedial measure that can be employed to assist the pilot in such situations. The results of this study are helpful in increasing pilots' situational awareness and enhancing automation during landings