scholarly journals Coelenterazine-Dependent Luciferases as a Powerful Analytical Tool for Research and Biomedical Applications

2020 ◽  
Vol 21 (20) ◽  
pp. 7465 ◽  
Author(s):  
Vasilisa V. Krasitskaya ◽  
Eugenia E. Bashmakova ◽  
Ludmila A. Frank
Keyword(s):  
Analytical Methods ◽  
Analytical Tool ◽  
Biological Research ◽  
Research Areas ◽  
Enzyme Substrate ◽  
Highly Sensitive ◽  
Powerful Analytical Tool ◽  
Fundamental Research ◽  
Common Group ◽  
First Time

The functioning of bioluminescent systems in most of the known marine organisms is based on the oxidation reaction of the same substrate—coelenterazine (CTZ), catalyzed by luciferase. Despite the diversity in structures and the functioning mechanisms, these enzymes can be united into a common group called CTZ-dependent luciferases. Among these, there are two sharply different types of the system organization—Ca2+-regulated photoproteins and luciferases themselves that function in accordance with the classical enzyme–substrate kinetics. Along with deep and comprehensive fundamental research on these systems, approaches and methods of their practical use as highly sensitive reporters in analytics have been developed. The research aiming at the creation of artificial luciferases and synthetic CTZ analogues with new unique properties has led to the development of new experimental analytical methods based on them. The commercial availability of many ready-to-use assay systems based on CTZ-dependent luciferases is also important when choosing them by first-time-users. The development of analytical methods based on these bioluminescent systems is currently booming. The bioluminescent systems under consideration were successfully applied in various biological research areas, which confirms them to be a powerful analytical tool. In this review, we consider the main directions, results, and achievements in research involving these luciferases.

Lupeol Alkanoates in Brazilian Propolis

2002 ◽  
Vol 57 (7-8) ◽  
pp. 721-726 ◽  
Author(s):  
Alberto S. Pereira ◽  
Evandro A. Nascimento ◽  
Francisco R. de Aquino Neto
Keyword(s):  
Mass Spectrometry ◽  
Native Plants ◽  
Analytical Tool ◽  
Material Sources ◽  
Minas Gerais State ◽  
Powerful Analytical Tool ◽  
High Resolution Gas Chromatography ◽  
Brazilian Propolis ◽  
First Time ◽  
The City

High temperature high resolution gas chromatography coupled to mass spectrometry (HTHRGC- MS) isa powerful analytical tool. In this work we applied this technique to the study of crude extracts of propolis collected near the city of Uberlândia - Minas Gerais State. Eucalyptus trees and native plants from “cerrado” (savannah) were the material sources disposable for the Apis mellifera bees. A lot of known propolis constituents were identified, however, several high molecular weight compounds including lupeol alkanoates were identified for first time in propolis.

Mass spectrometry as a powerful analytical tool for the characterization of indoor airborne microplastics and nanoplastics

2021 ◽  
Author(s):  
Milica Velimirovic ◽  
Kristof Tirez ◽  
Sandra Verstraelen ◽  
Evelien Frijns ◽  
Sylvie Remy ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Particle Size ◽  
Analytical Methods ◽  
Analytical Tool ◽  
Chemical Identification ◽  
Size Determination ◽  
Particle Size Determination ◽  
Powerful Analytical Tool ◽  
Identification And Quantification

Development of analytical methods for the characterization (particle size determination, chemical identification, and quantification) of the low µm-range microplastics (MPs; 1-10 µm) and nanoplastics (NPs; 1 nm-1 µm) in air...

scholarly journals Environmental Factors do not Affect the Phenolic Profile of Hypericum perforatum Growing Wild in Bosnia and Herzegovina

2017 ◽  
Vol 12 (9) ◽  
pp. 1934578X1701200 ◽  
Author(s):  
Sanja Ćavar Zeljković ◽  
Erna Karalija ◽  
Adisa Parić ◽  
Edina Muratović ◽  
Petr Tarkowski
Keyword(s):  
Environmental Factors ◽  
Bosnia And Herzegovina ◽  
Hypericum Perforatum ◽  
Analytical Tool ◽  
Phenolic Profile ◽  
Glycosidic Bonds ◽  
Fractionation Procedure ◽  
Powerful Analytical Tool ◽  
Hypericum Perforatum L ◽  
First Time

Using appropriate isolation and fractionation procedure, and UHPLC-MS/MS as powerful analytical tool, comprehensive phenolic acid profile of leaves and flowers of Hypericum perforatum L., growing wild in Bosnia and Herzegovina, has been analyzed for the first time. The phenolic acids were isolated from plant tissue, liberated from esters and glycosidic bonds, and then analyzed as free acids. Results show that free forms of caffeic and chlorogenic acid were the most abundant. Generally, the content of acids is higher in flowers than in leaves, but environmental factors do not significantly influence chemical composition of this medicinal plant.

scholarly journals HPLC-ESI-QTOF-MS as a Powerful Analytical Tool for Characterising Phenolic Compounds in Olive-leaf Extracts

2012 ◽  
Vol 24 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Rosa Quirantes-Piné ◽  
Jesús Lozano-Sánchez ◽  
Miguel Herrero ◽  
Elena Ibáñez ◽  
Antonio Segura-Carretero ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Analytical Tool ◽  
Olive Leaf ◽  
Leaf Extracts ◽  
Powerful Analytical Tool

Intramolecular photoinitiator induced atom transfer radical polymerization for electrochemical DNA detection

The Analyst ◽  
2020 ◽  
Vol 145 (3) ◽  
pp. 858-864
Author(s):  
Ligang Ma ◽  
Qianrui Liu ◽  
Lihe Jian ◽  
Shan Ye ◽  
Xiaoke Zheng ◽  
...  
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Electrochemical Biosensor ◽  
Dna Detection ◽  
Atom Transfer ◽  
Highly Sensitive ◽  
Electrochemical Dna Detection ◽  
First Time

A novel electrochemical biosensor was reported for the first time to achieve highly sensitive DNA detection based on photoinduced atom transfer radical polymerization (photoATRP).

scholarly journals Analysis of free and protein-bound nitrotyrosine in human plasma by a gas chromatography/mass spectrometry method that avoids nitration artifacts

2000 ◽  
Vol 345 (3) ◽  
pp. 453-458 ◽  
Author(s):  
Matthew T. FROST ◽  
Barry HALLIWELL ◽  
Kevin P. MOORE
Keyword(s):  
Reactive Nitrogen Species ◽  
Plasma Proteins ◽  
Biological Fluids ◽  
Plasma Concentrations ◽  
Normal Subjects ◽  
Gas Chromatography Mass Spectrometry ◽  
Highly Sensitive ◽  
Acidic Conditions ◽  
First Time

Measurement of nitrotyrosine in biological fluids and tissues is increasingly being used to monitor the production of reactive nitrogen species in vivo. The detection of nitrotyrosine in vivo has been reported with the use of a variety of methods including immunoassay, HPLC and GLC/MS. The validity of HPLC and immunoassays have been questioned with regard to their selectivity and sensitivity limits. In principle, the measurement of nitrotyrosine by GLC/MS permits a highly specific, highly sensitive and fully quantitative assay. The nitration of tyrosine under acidic conditions in the presence of nitrite is well documented. Derivatization for the full quantification of nitrotyrosine by using GLC/MS can lead to the artifactual nitration of tyrosine if performed under acidic conditions in the presence of nitrite. We describe a novel alkaline method for the hydrolysis and derivatization of nitrotyrosine and tyrosine, and demonstrate its applicability to the measurement of plasma concentrations of both free and protein-bound nitrotyrosine and tyrosine. A detection limit of 1 pg for nitrotyrosine and 100 pg for tyrosine has been achieved. Our method allows, for the first time, the analysis of free and protein-bound nitrotyrosine and tyrosine in biological samples. The plasma concentrations (means±S.E.M.) of free tyrosine and nitrotyrosine in eight normal subjects were 12±0.6 μg/ml and 14±0.7 ng/ml respectively. Plasma proteins contained tyrosine and nitrotyrosine at 60.7±1.7 μg/mg and 2.7±0.4 ng/mg respectively.

scholarly journals The growth of interest for astronomical X-ray polarimetry

2018 ◽  
Author(s):  
Frédéric Marin
Keyword(s):  
Quantitative Assessment ◽  
Supernova Remnant ◽  
Scientific Literature ◽  
High Energy ◽  
X Ray ◽  
Highly Sensitive ◽  
In The Beginning ◽  
First Time

Astronomical X-ray polarimetry was first explored in the end of the 60's by pioneering rocket instruments. The craze arising from the first discoveries on stellar and supernova remnant X-ray polarization led to the addition of X-ray polarimeters on-board of early satellites. Unfortunately, the inadequacy of the diffraction and scattering technologies required to measure polarization with respect to the constraints driven by X-ray mirrors and detectors, coupled to long integration times, slowed down the field for almost 40 years. Thanks to the development of new, highly sensitive, compact X-ray polarimeters in the beginning of the 2000's, the possibility to observe astronomical X-ray polarization is rising again and scientists are now ready to explore the high energy sky thanks to modern X-ray polarimeters. In the forthcoming years, several X-ray missions (both rockets, balloons and satellites) will open a new observational windows. A wind of renewal blows over the area of X-ray polarimetry and this paper presents for the first time a quantitative assessment, all based on scientific literature, of the growth of interest for astronomical X-ray polarimetry.

scholarly journals A Method for Actin Filament Tracking in Fluorescent Microscopy Images

2020 ◽  
pp. paper37-1-paper37-10
Author(s):  
Danil Kononykhin ◽  
Valentina Berg ◽  
Andrey Krylov ◽  
Dmitry Sorokin
Keyword(s):  
Nearest Neighbor ◽  
Fluorescent Microscopy ◽  
Image Sequences ◽  
Biological Research ◽  
Tracking Accuracy ◽  
Actual Problem ◽  
Quality Metric ◽  
Ridge Detection ◽  
Research Areas ◽  
Microscopy Image

The automated tracking of subcellular structures in live microscopy image sequences is an actual problem in many biological research areas. A universal solution for this problem still does not exist due to a huge variety of data of different nature. In this work, we propose an algorithm for tracking actin filaments in 2D fluorescent image sequences. The filaments are moving in a random and abrupt manner frequently crossing each other. We used steerable filters based ridge detection followed by crossing filaments correction algorithm for filaments detection. The tracking was performed using a greedy nearest neighbor method. The quantitative evaluation of our approach was performed on several manually annotated image sequences using the object tracking quality metric MOTA. It was shown that the proposed approach outperforms an existing approach in tracking accuracy. In addition, the proposed approach allows processing crossed filaments, unlike the existing methods.

scholarly journals Highly sensitive p-type 4H-SiC van der Pauw sensor

RSC Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 3009-3013 ◽  
Author(s):  
Tuan-Khoa Nguyen ◽  
Hoang-Phuong Phan ◽  
Jisheng Han ◽  
Toan Dinh ◽  
Abu Riduan Md Foisal ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Strain Sensor ◽  
Highly Sensitive ◽  
Van Der Pauw ◽  
P Type ◽  
First Time

This paper presents for the first time a p-type 4H silicon carbide (4H-SiC) van der Pauw strain sensor by utilizing the strain induced effect in four-terminal devices.

The chick embryo chorioallantoic membrane model: a research approach for ex vivo and in vivo experiments

2021 ◽  
Vol 28 ◽  
Author(s):  
Ana Isabel Fraguas-Sánchez ◽  
Cristina Martín-Sabroso ◽  
Ana Isabel Torres-Suárez
Keyword(s):  
Animal Models ◽  
Chorioallantoic Membrane ◽  
New Drugs ◽  
Biological Research ◽  
Research Areas ◽  
Chick Chorioallantoic Membrane ◽  
Biodistribution Studies ◽  
Toxicological Studies ◽  
Cam Model

Background: The chick chorioallantoic membrane (CAM) model has attracted a great deal of interest in pharmaceutical and biological research as an alternative or complementary in vivo assay to animal models. Traditionally, CAM assay has been widely used to perform some toxicological studies, specifically to evaluate the skin, ocular and embryo toxicity of new drugs and formulations, and perform angiogenesis studies. Due to the possibility to generate the tumors onto the CAM, this model has also become an excellent strategy to evaluate the metastatic potential of different tumours and test the efficacy of novel anticancer therapies in vivo. Moreover, in the recent years, its use has considerably grown in other research areas, including the evaluation of new anti-infective agents, the development of biodistribution studies and tissue engineering research. Objectives: This manuscript provides a critical overview of the use of CAM model in pharmaceutical and biological research, especially to test the toxicity of new drugs and formulations and the biodistribution and the efficacy of novel anticancer and anti-infective therapies, analyzing its advantages and disadvantages compared to animal models. Conclusion: The chick chorioallantoic membrane model shows great utility in several research areas, such as cancer, toxicology, biodistribution studies and anti-infective therapies. In fact, it has become an intermediate stage between in vitro experiments and animal studies, and, in the case of toxicological studies (skin and ocular toxicity), has even replaced the animal models.

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