scholarly journals Quantum magnetic imaging of iron organelles within the pigeon cochlea

2021 ◽  
Vol 118 (47) ◽  
pp. e2112749118
Author(s):  
Robert W. de Gille ◽  
Julia M. McCoey ◽  
Liam T. Hall ◽  
Jean-Philippe Tetienne ◽  
E. Pascal Malkemper ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Magnetic Particle ◽  
Imaging Techniques ◽  
Iron Storage ◽  
Magnetic Imaging ◽  
Geomagnetic Fields ◽  
The Individual ◽  
Individual Particles

The ability of pigeons to sense geomagnetic fields has been conclusively established despite a notable lack of determination of the underlying biophysical mechanisms. Quasi-spherical iron organelles previously termed “cuticulosomes” in the cochlea of pigeons have potential relevance to magnetoreception due to their location and iron composition; however, data regarding the magnetic susceptibility of these structures are currently limited. Here quantum magnetic imaging techniques are applied to characterize the magnetic properties of individual iron cuticulosomes in situ. The stray magnetic fields emanating from cuticulosomes are mapped and compared to a detailed analytical model to provide an estimate of the magnetic susceptibility of the individual particles. The images reveal the presence of superparamagnetic and ferrimagnetic domains within individual cuticulosomes and magnetic susceptibilities within the range 0.029 to 0.22. These results provide insights into the elusive physiological roles of cuticulosomes. The susceptibilities measured are not consistent with a torque-based model of magnetoreception, placing iron storage and stereocilia stabilization as the two leading putative cuticulosome functions. This work establishes quantum magnetic imaging as an important tool to complement the existing array of techniques used to screen for potential magnetic particle–based magnetoreceptor candidates.

scholarly journals Selected In Situ Hybridization Methods: Principles and Application

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3874
Author(s):  
Dominika Veselinyová ◽  
Jana Mašlanková ◽  
Katarina Kalinová ◽  
Helena Mičková ◽  
Mária Mareková ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Imaging Techniques ◽  
Cell Communication ◽  
Probe Design ◽  
Rapid Progress ◽  
In Situ Techniques ◽  
Different Types ◽  
Laboratory Procedures ◽  
The Individual

We are experiencing rapid progress in all types of imaging techniques used in the detection of various numbers and types of mutation. In situ hybridization (ISH) is the primary technique for the discovery of mutation agents, which are presented in a variety of cells. The ability of DNA to complementary bind is one of the main principles in every method used in ISH. From the first use of in situ techniques, scientists paid attention to the improvement of the probe design and detection, to enhance the fluorescent signal intensity and inhibition of cross-hybrid presence. This article discusses the individual types and modifications, and is focused on explaining the principles and limitations of ISH division on different types of probes. The article describes a design of probes for individual types of in situ hybridization (ISH), as well as the gradual combination of several laboratory procedures to achieve the highest possible sensitivity and to prevent undesirable events accompanying hybridization. The article also informs about applications of the methodology, in practice and in research, to detect cell to cell communication and principles of gene silencing, process of oncogenesis, and many other unknown processes taking place in organisms at the DNA/RNA level.

scholarly journals Development of an in-situ SEOP 3 He Neutron Spin Filter for Magnetic Imaging Techniques

2017 ◽  
Vol 88 ◽  
pp. 231-236 ◽  
Author(s):  
H. Hayashida ◽  
K. Hiroi ◽  
T. Oku ◽  
H. Kira ◽  
K. Sakai ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Neutron Spin ◽  
Spin Filter ◽  
Magnetic Imaging

scholarly journals The Anomalous Influence of Polyelectrolyte Concentration on the Deposition and Nanostructure of Poly(ethyleneimine)/Poly(acrylic acid) Multilayers

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2141 ◽  
Author(s):  
Martin Müller
Keyword(s):  
Acrylic Acid ◽  
Attenuated Total Reflection ◽  
Silicon Substrates ◽  
Acid Base ◽  
Exponential Relationship ◽  
Individual Adsorption ◽  
The Individual ◽  
Poly Acrylic Acid

The deposition and nanostructure of polyelectrolyte (PEL) multilayers (PEMs) of branched poly(ethyleneimine)/poly(acrylic acid) (PEI/PAA) onto silicon substrates was studied in terms of the dependence of pH and the PEL concentration (cPEL) in the individual adsorption steps z. Both a commercial automatic dipping device and a homebuilt automatic stream coating device (flow cell) were used. Gravimetry, SFM, transmission (TRANS) and in situ attenuated total reflection (ATR) FTIR spectroscopy were used for the quantitative determination of the adsorbed amount, thickness, chemical composition and morphology of deposited PEMs, respectively. Firstly, the combination of pH = 10 for PEI and pH = 4 for PAA, where both PEL were predominantly in the neutral state, resulted in an extraordinarily high PEM deposition, while pH combinations, where one PEL component was charged, resulted in a significantly lower PEM deposition. This was attributed to both PEL conformation effects and acid/base interactions between basic PEI and acidic PAA. Secondly, for that pH combination an exponential relationship between PEM thickness and adsorption step z was found. Thirdly, based on the results of three independent methods, the course of the deposited amount of a PEM-10 (z = 10) versus cPEL in the range 0.001 to 0.015 M at pH = 10/4 was non-monotonous showing a pronounced maximum at cPEL = 0.005 M. Analogously, for cPEL = 0.005 M a maximum of roughness and structure size was found. Fourthly, related to that finding, in situ ATR-FTIR measurements gave evidence for the release of outermost located PEI upon PAA immersion (even step) and of outermost PAA upon PEI immersion (odd step) under formation of PEL complexes in solution. These studies help us to prepare PEL-based films with a defined thickness and morphology for interaction with biofluids in the biomedical and food fields.

scholarly journals DETERMINATION OF PEAT ASH FUSIBILITY OF KIROV REGION DEPOSITS

2019 ◽  
Vol 20 (11-12) ◽  
pp. 27-33
Author(s):  
V. A. Kuzmin ◽  
I. A. Zagrai ◽  
I. A. Desiatkov
Keyword(s):  
Fly Ash ◽  
Chemical Composition ◽  
Melting Temperature ◽  
Operating Temperature ◽  
Melting Characteristics ◽  
Steam Boilers ◽  
Ash Fusibility ◽  
The Individual ◽  
Individual Particles

The paper deals with the issues related to the effect of slagging within the steam boilers furnaces and shows the determination results on peat ash fusibility of Kirov region deposits. Fusibility properties of peat ash (temperatures of deformation, sphere, hemisphere and flow) from the four industrial areas (Dymny, Pishchalsky, Karinsky, Gorokhovsky) depending on its chemical composition are presented. Melting temperature of the mineral part of the peat, determined by GOST, is averaged and does not reflect the actual melting temperature of the individual particles in fly ash. The existence of such separate particles having a melting temperature below the average melting temperature of the ash makes it difficult to find the operating temperature of the torch to reach the minimum of the furnace slagging during peat combustion. The comparison of melting characteristics of peat ash with the reference literature data is performed. The initial slagging temperature is calculated depending on the ratio of the acidic and basic oxides in peat ash.

scholarly journals Nanoscale magnetic imaging of ferritins in a single cell

2019 ◽  
Vol 5 (4) ◽  
pp. eaau8038 ◽  
Author(s):  
Pengfei Wang ◽  
Sanyou Chen ◽  
Maosen Guo ◽  
Shijie Peng ◽  
Mengqi Wang ◽  
...  
Keyword(s):  
Single Cell ◽  
Imaging Techniques ◽  
Nitrogen Vacancy ◽  
Nanometer Scale ◽  
Magnetic Imaging ◽  
Intracellular Proteins ◽  
Nv Center ◽  
A Cell ◽  
Endogenous Proteins

The in situ measurement of the distribution of biomolecules inside a cell is one of the important goals in life science. Among various imaging techniques, magnetic imaging (MI) based on the nitrogen-vacancy (NV) center in diamond provides a powerful tool for the biomolecular research, while the nanometer-scale MI of intracellular proteins remains a challenge. Here, we use ferritin as a demonstration to realize the MI of endogenous proteins in a single cell using the NV center as the sensor. With the scanning, intracellular ferritins are imaged with a spatial resolution of ca. 10 nm, and ferritin-containing organelles are colocalized by correlative MI and electron microscopy. The approach paves the way for nanoscale MI of intracellular proteins.

Topographical mapping of ribosomal RNAs in situ by electron spectroscopic imaging

1984 ◽  
Vol 42 ◽  
pp. 690-691
Author(s):  
M. Boublik ◽  
G.T. Oostergetel ◽  
B. Frankland ◽  
F.P. Ottensmeyer
Keyword(s):  
Spectroscopic Techniques ◽  
Rna Molecules ◽  
Macromolecular System ◽  
Unique Distribution ◽  
Topographical Mapping ◽  
The Individual ◽  
And Function ◽  
Electron Energy Loss

Visualization of the in situ location of the individual components of any macromolecular system is important for understanding its assembly, interactions, and function. Ribosomes, which are small cellular organelles involved in protein synthesis are high molecular weight nucleoprotein complexes composed only of proteins and RNAs. This “simple” composition of ribosomes enables us topographical studies directed either towards localization of the individual ribosomal protein and RNA molecules or merely to the determination of the distribution of the protein and RNA moieties within the ribosome and its subunits. We have utilized the recent progress in the development of microanalytical electron spectroscopic techniques, electron energy loss spectroscopy (EELS) in particular, and the unique distribution of the phosphorus atoms on the ribosome (the phosphorus atoms are present only in the structural backbone of the rRNA) for the direct tracing of the RNA molecules in situ.

ANALYSIS FOR MAGNETITE UTILIZING MAGNETIC SUSCEPTIBILITY

Geophysics ◽  
1966 ◽  
Vol 31 (2) ◽  
pp. 398-409 ◽  
Author(s):  
P. D. Shandley ◽  
L. O. Bacon
Keyword(s):  
Magnetic Susceptibility ◽  
Chemical Analysis ◽  
Metallic Iron ◽  
Magnetic Minerals ◽  
Magnetite Content ◽  
Subsequent Calculation ◽  
The Individual ◽  
Direct Readout ◽  
Individual Particles ◽  
Iron Bearing

The analysis for magnetite or “magnetite equivalent” by means of magnetic susceptibility is more rapid, lower in cost, and in general, as precise as other methods of analysis. “Magnetite equivalent” analysis is affected by grain size if the individual particles are less than 40 microns in diameter, by the remnant magnetization if greater than about 12 percent of saturation magnetization, and by the presence of other magnetic minerals. The presence of other magnetic minerals does not reflect as great an error in the final result using the susceptibility method as in other methods. Davis tube separation as a method for magnetite analysis is affected by other magnetic minerals but is mainly dependent upon degree of mineral liberation by grinding. Chemical analysis with the subsequent calculation of magnetite content is in error due to presence of other iron‐bearing minerals whether magnetic or nonmagnetic and is particularly affected by the presence of metallic iron from sample preparation. Metallic iron apparently enters solution by the following reaction: [Formula: see text] Thus, one unit of metallic iron would be counted as approximately 12 units of magnetite in the calculation of magnetite content. Analysis for “magnetite equivalent” and chemical analysis for total soluble iron can provide an accurate evaluation of the amount of nonmagnetic iron in any particular ore, especially in mixed magnetite‐hematite ores. Equipment for direct readout of grams magnetite per 100 cc was designed using the differential transformer principle. Calibration is linear below 20 grams magnetite per 100 cc, and measurement of apparent density of sample readily converts the readings to percent magnetite by weight.

scholarly journals Combination of DNA in situ hybridization and immunocytochemical detection of nucleolar proteins: a contribution to the functional mapping of the human genome by fluorescence microscopy.

1994 ◽  
Vol 42 (2) ◽  
pp. 149-154 ◽  
Author(s):  
I Leger ◽  
M Robert-Nicoud ◽  
G Brugal
Keyword(s):  
In Situ Hybridization ◽  
Viral Infections ◽  
Imaging Techniques ◽  
Simultaneous Detection ◽  
Chromosome 1 ◽  
Confocal Laser ◽  
Nucleolar Proteins ◽  
Immunocytochemical Detection ◽  
The Individual

The recent application of DNA cloning and non-radioactive in situ hybridization techniques has strengthened the hypothesis of an ordered chromatin structure in interphase nuclei. The arrangement of specific chromosomal regions is not random and is strongly suspected to vary with functional activity. The combination of in situ hybridization and immunocytochemistry, allowing simultaneous detection of nucleic acid sequences and specific antigens in the same nucleus, has already made significant contributions to the study of gene expression, to simultaneous karyotyping and phenotyping of tumor cells, and to in situ analysis of viral infections. This report emphasizes the considerable interest of such combined techniques for functional in situ mapping of the genome at the individual cell level. We propose a method that combines fluorescence immunocytochemical detection of nucleolar proteins and fluorescence in situ hybridization of centromeric and telomeric probes specific for chromosome 1 in two cultured human cell lines. The preparative constraints for a broad application of this procedure are defined so that the cell preparations can be further analyzed by fluorescence microscopic imaging techniques and confocal laser scan microscopy. The two selected sequences of the human chromosome 1 can be localized in the nucleus with respect to nucleolar proteins in a one-step fluorescence microscopic observation.

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