Intracellular Localization of Cerium. A Microanalytical Study using an Electron Microprobe and Ionic Microanalysis

1989 ◽  
Vol 8 (6) ◽  
pp. 511-520 ◽  
Author(s):  
J.P. Berry ◽  
R. Masse ◽  
F. Escaig ◽  
P. Galle
Keyword(s):  
Bone Marrow ◽  
Spatial Resolution ◽  
Electron Microprobe ◽  
Intracellular Localization ◽  
High Sensitivity ◽  
Radiological Protection ◽  
Aerosol Exposure ◽  
Low Concentrations ◽  
Intracellular Metabolism ◽  
Very High

Radioactive cerium is a nuclear toxicant. Metallic cerium is used in industry. Aspects of the intracellular metabolism of this element were studied following intraperitoneal injection and aerosol exposure in rat. Two microanalytic methods, an electron microprobe and ionic microanalysis, enabled the sites of incorporation and the process of intracellular concentration of cerium to be determined in the liver, lung, kidney, bone marrow and bone tissue. The very high sensitivity of ionic analysis enabled very low concentrations of cerium to be detected with a spatial resolution of 0.5 μm. Microanalysis by electron microprobe permitted: (i) the lysosomal localization of cerium to be determined; and (ii) the lysosomal coprecipitation of cerium with phosphorus to be demonstrated. Results are discussed in relation to aspects of radiological protection.

High spatial resolution at very high sensitivity using synchrotron radiation excited XPS

1989 ◽  
Vol 60 (7) ◽  
pp. 2172-2175 ◽  
Author(s):  
M. Schaible ◽  
H. Petersen ◽  
W. Braun ◽  
E.‐E. Koch
Keyword(s):  
Synchrotron Radiation ◽  
Spatial Resolution ◽  
High Spatial Resolution ◽  
High Sensitivity ◽  
Very High

Materials science of cells: Electron probe x-ray microanalysis and x-ray mapping in biology

1989 ◽  
Vol 47 ◽  
pp. 238-239
Author(s):  
Andrew P. Somlyo
Keyword(s):  
Spatial Resolution ◽  
Electron Probe ◽  
Materials Science ◽  
High Sensitivity ◽  
Specimen Preparation ◽  
X Ray ◽  
Low Concentrations ◽  
Freeze Dried ◽  
And Control

The general aims of Electron Probe X-ray Microanalysis (EPMA) in Biology is similar to that in Materials Science: the determination of composition at sub-micron resolution. Special requirements include stringent precautions for specimen preparation, high sensitivity for detecting low concentrations of elements avoidance, and if not possible, quantitation and control of radiation damage, and spatial resolution of at least tens of nanometers.Special precautions for specimen preparation are dictated by the fact that biological materials exist in an aqueous milieu, and one of the most common objectives of biological EPMA is the localization and quantitation of diffusible elements. Therefore, specimen preparatory techniques must include handling of live tissues in a manner that maintains normal physiological states, and rapid freezing to trap diffusible elements in their physiological compartments. In order to obtain high spatial resolution, ultrathin cryosections have to be obtained, freeze dried and transferred to the microscope under conditions that prevent elemental translocations. Specimen temperatures during cryo-sectioning are usually at about -100°centigrade.

Small-volume vitrification and rapid warming yield high survivals of one-cell rat embryos in cryotubes

2021 ◽  
Author(s):  
Yasuyoshi Fukuda ◽  
Misako Higashiya ◽  
Takahiro Obata ◽  
Keita Basaki ◽  
Megumi Yano ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Small Volume ◽  
Sucrose Solution ◽  
High Concentration ◽  
Rat Embryos ◽  
Low Concentrations ◽  
Intracellular Ice Formation ◽  
Intracellular Ice ◽  
Warming Rate ◽  
Very High

Abstract To cryopreserve cells, it is essential to avoid intracellular ice formation during cooling and warming. One way to achieve this is to convert the water inside the cells into a non-crystalline glass. It is currently believed that to accomplish this vitrification, the cells must be suspended in a very high concentration (20–40%) of a glass-inducing solute, and subsequently cooled very rapidly. Herein, we report that this belief is erroneous with respect to the vitrification of one-cell rat embryos. In the present study, one-cell rat embryos were vitrified with 5 μL of EFS10 (a mixture of 10% ethylene glycol, 27% Ficoll, and 0.45 M sucrose) in cryotubes at a moderate cooling rate, and warmed at various rates. Survival was assessed according to the ability of the cells to develop into blastocysts and to develop to term. When embryos were vitrified at a 2,613 °C/min cooling rate and thawed by adding 1 mL of sucrose solution (0.3 M, 50 °C) at a warming rate of 18,467 °C/min, 58.1 ± 3.5% of the EFS10-vitrified embryos developed into blastocysts, and 50.0 ± 4.7% developed to term. These rates were similar to those of non-treated intact embryos. Using a conventional cryotube, we achieved developmental capabilities in one-cell rat embryos by rapid warming that were comparable to those of intact embryos, even using low concentrations (10%) of cell-permeating cryoprotectant and at low cooling rates.

scholarly journals All-Dielectric Metasurface for Sensing Microcystin-LR

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1363
Author(s):  
Binze Ma ◽  
Ao Ouyang ◽  
Juechen Zhong ◽  
Pavel A. Belov ◽  
Ravindra Kumar Sinha ◽  
...  
Keyword(s):  
Quality Factor ◽  
Bound States ◽  
High Sensitivity ◽  
Concentration Limit ◽  
Specific Recognition ◽  
Low Concentrations ◽  
Freshwater Bodies ◽  
Toxic Pollutant ◽  
Small Change ◽  
Dielectric Metasurface

Sensing Microcystin-LR (MC-LR) is an important issue for environmental monitoring, as the MC-LR is a common toxic pollutant found in freshwater bodies. The demand for sensitive detection method of MC-LR at low concentrations can be addressed by metasurface-based sensors, which are feasible and highly efficient. Here, we demonstrate an all-dielectric metasurface for sensing MC-LR. Its working principle is based on quasi-bound states in the continuum mode (QBIC), and it manifests a high-quality factor and high sensitivity. The dielectric metasurface can detect a small change in the refractive index of the surrounding environment with a quality factor of ~170 and a sensitivity of ~788 nm/RIU. MC-LR can be specifically identified in mixed water with a concentration limit of as low as 0.002 μg/L by a specific recognition technique for combined antigen and antibody. Furthermore, the demonstrated detection of MC-LR can be extended to the identification and monitoring of other analytes, such as viruses, and the designed dielectric metasurface can serve as a monitor platform with high sensitivity and high specific recognition capability.

scholarly journals An Evaluation of Pixel- and Object-Based Tree Species Classification in Mixed Deciduous Forests Using Pansharpened Very High Spatial Resolution Satellite Imagery

2021 ◽  
Vol 13 (10) ◽  
pp. 1868
Author(s):  
Martina Deur ◽  
Mateo Gašparović ◽  
Ivan Balenović
Keyword(s):  
Spatial Resolution ◽  
Satellite Imagery ◽  
Tree Species ◽  
Classification Accuracy ◽  
New Technologies ◽  
Deciduous Forest ◽  
Species Classification ◽  
Tree Species Classification ◽  
Object Based ◽  
Very High

Quality tree species information gathering is the basis for making proper decisions in forest management. By applying new technologies and remote sensing methods, very high resolution (VHR) satellite imagery can give sufficient spatial detail to achieve accurate species-level classification. In this study, the influence of pansharpening of the WorldView-3 (WV-3) satellite imagery on classification results of three main tree species (Quercus robur L., Carpinus betulus L., and Alnus glutinosa (L.) Geartn.) has been evaluated. In order to increase tree species classification accuracy, three different pansharpening algorithms (Bayes, RCS, and LMVM) have been conducted. The LMVM algorithm proved the most effective pansharpening technique. The pixel- and object-based classification were applied to three pansharpened imageries using a random forest (RF) algorithm. The results showed a very high overall accuracy (OA) for LMVM pansharpened imagery: 92% and 96% for tree species classification based on pixel- and object-based approach, respectively. As expected, the object-based exceeded the pixel-based approach (OA increased by 4%). The influence of fusion on classification results was analyzed as well. Overall classification accuracy was improved by the spatial resolution of pansharpened images (OA increased by 7% for pixel-based approach). Also, regardless of pixel- or object-based classification approaches, the influence of the use of pansharpening is highly beneficial to classifying complex, natural, and mixed deciduous forest areas.

scholarly journals High spatial resolution photo mosaicking for the monitoring of coralligenous reefs

Coral Reefs ◽  
2021 ◽  
Author(s):  
E. Casoli ◽  
D. Ventura ◽  
G. Mancini ◽  
D. S. Pace ◽  
A. Belluscio ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
High Spatial Resolution ◽  
Low Cost ◽  
Pixel Resolution ◽  
Recording Apparatus ◽  
Assemblage Composition ◽  
Very High Spatial Resolution ◽  
Vertical Walls ◽  
Non Destructive ◽  
Very High

AbstractCoralligenous reefs are characterized by large bathymetric and spatial distribution, as well as heterogeneity; in shallow environments, they develop mainly on vertical and sub-vertical rocky walls. Mainly diver-based techniques are carried out to gain detailed information on such habitats. Here, we propose a non-destructive and multi-purpose photo mosaicking method to study and monitor coralligenous reefs developing on vertical walls. High-pixel resolution images using three different commercial cameras were acquired on a 10 m2 reef, to compare the effectiveness of photomosaic method to the traditional photoquadrats technique in quantifying the coralligenous assemblage. Results showed very high spatial resolution and accuracy among the photomosaic acquired with different cameras and no significant differences with photoquadrats in assessing the assemblage composition. Despite the large difference in costs of each recording apparatus, little differences emerged from the assemblage characterization: through the analysis of the three photomosaics twelve taxa/morphological categories covered 97–99% of the sampled surface. Photo mosaicking represents a low-cost method that minimizes the time spent underwater by divers and capable of providing new opportunities for further studies on shallow coralligenous reefs.

scholarly journals The Double Face of Ketamine—The Possibility of Its Identification in Blood and Beverages

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 813
Author(s):  
Magdalena Świądro ◽  
Paweł Stelmaszczyk ◽  
Irena Lenart ◽  
Renata Wietecha-Posłuszny
Keyword(s):  
Date Rape ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Heroin Addiction ◽  
Assisted Extraction ◽  
Low Concentrations ◽  
High Concentrations ◽  
Rosé Wine ◽  
Tof Ms

The purpose of this study was to develop and validate a high-sensitivity methodology for identifying one of the most used drugs—ketamine. Ketamine is used medicinally to treat depression, alcoholism, and heroin addiction. Moreover, ketamine is the main ingredient used in so-called “date-rape” pills (DRP). This study presents a novel methodology for the simultaneous determination of ketamine based on the Dried Blood Spot (DBS) method, in combination with capillary electrophoresis coupled with a mass spectrometer (CE-TOF-MS). Then, 6-mm circles were punched out from DBS collected on Whatman DMPK-C paper and extracted using microwave-assisted extraction (MAE). The assay was linear in the range of 25–300 ng/mL. Values of limits of detection (LOD = 6.0 ng/mL) and quantification (LOQ = 19.8 ng/mL) were determined based on the signal to noise ratio. Intra-day precision at each determined concentration level was in the range of 6.1–11.1%, and inter-day between 7.9–13.1%. The obtained precision was under 15.0% (for medium and high concentrations) and lower than 20.0% (for low concentrations), which are in accordance with acceptance criteria. Therefore, the DBS/MAE/CE-TOF-MS method was successfully checked for analysis of ketamine in matrices other than blood, i.e., rose wine and orange juice. Moreover, it is possible to identify ketamine in the presence of flunitrazepam, which is the other most popular ingredient used in DRP. Based on this information, the selectivity of the proposed methodology for identifying ketamine in the presence of other components of rape pills was checked.

Very high sensitivity optical modulators based on band filling effect in GaInAs quantum wells

1990 ◽  
Author(s):  
T.Y. Chang ◽  
J.E. Zucker ◽  
K.L. Jones ◽  
N.J. Sauer ◽  
B. Tell ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Sensitivity ◽  
Optical Modulators ◽  
Band Filling ◽  
Very High
Sign in / Sign up

Export Citation Format

Share Document