In situ UHVEM observation of atomic ordering in magnetic nanoparticles using a direct detection camera

We have determined optimal conditions for the detection of mRNA sequences in cultured cells by nonradioactive in situ hybridization. For this purpose a number of different cell lines have been used: rat 9G cells for the detection of human cytomegalovirus immediate early mRNA, and HeLa as well as 5637 carcinoma cells for the detection of housekeeping gene mRNAs. Extensive optimization of fixation and pretreatment conditions revealed that most intense hybridization signals are obtained when cells are grown on glass microscope slides, fixed with a mixture of formaldehyde and acetic acid, pretreated with pepsin and denatured prior to hybridization. In addition, we also studied the potential of fluorochromized probes for the direct detection of multiple RNA sequences. The optimized in situ hybridization procedure revealed that immediate early mRNA transcripts are, in addition to a cytoplasmic localization, localized within nuclei of rat 9G cells. Double hybridization experiments showed that intron and exon sequences colocalize within the main nuclear signal. In addition, the presence of small, intron-specific, fluorescent spots scattered around the main nuclear signals indicates that intron sequences which are spliced out can be visualized. Additional information about the functioning of cells could be obtained by the detection of mRNA simultaneously with bromodeoxyuridine, incorporated during S-phase, or its cognate protein. The sensitivity of these methods is such that mRNAs of abundantly expressed housekeeping genes can be detected in a variety of cell lines with high signal to noise ratios.

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In situ immobilized palladium nanoparticles on surface of poly-methyldopa coated-magnetic nanoparticles (Fe3O4@PMDA/Pd): A magnetically recyclable nanocatalyst for cyanation of aryl halides with K4[Fe(CN)6]

Journal of Catalysis ◽

10.1016/j.jcat.2018.07.008 ◽

2018 ◽

Vol 365 ◽

pp. 204-212 ◽

Cited By ~ 41

Author(s):

Hojat Veisi ◽

Saba Hemmati ◽

Parisa Safarimehr

Keyword(s):

Magnetic Nanoparticles ◽

Palladium Nanoparticles ◽

Aryl Halides ◽

Magnetic Nanoparticles Fe3o4

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Direct detection of Staphylococcus aureus in positive blood cultures through molecular beacon-based fluorescence in situ hybridization

Journal of Microbiological Methods ◽

10.1016/j.mimet.2019.02.007 ◽

2019 ◽

Vol 159 ◽

pp. 34-41 ◽

Cited By ~ 2

Author(s):

Bo Zhang ◽

Yibeibaihan Maimaiti ◽

Chunyan Liu ◽

Jing Li ◽

Haiye Wang ◽

...

Keyword(s):

Staphylococcus Aureus ◽

In Situ Hybridization ◽

Fluorescence In Situ Hybridization ◽

Molecular Beacon ◽

Direct Detection ◽

Blood Cultures

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High-temperature in situ crystallographic observation of reversible gas sorption in impermeable organic cages

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1504586112 ◽

2015 ◽

Vol 112 (46) ◽

pp. 14156-14161 ◽

Cited By ~ 18

Author(s):

Seung Bin Baek ◽

Dohyun Moon ◽

Robert Graf ◽

Woo Jong Cho ◽

Sung Woo Park ◽

...

Keyword(s):

Single Crystal ◽

High Temperatures ◽

Direct Detection ◽

Variable Temperature ◽

Magic Angle Spinning ◽

Magic Angle ◽

X Ray Diffraction ◽

X Ray ◽

Dynamic Motion

Crystallographic observation of adsorbed gas molecules is a highly difficult task due to their rapid motion. Here, we report the in situ single-crystal and synchrotron powder X-ray observations of reversible CO2 sorption processes in an apparently nonporous organic crystal under varying pressures at high temperatures. The host material is formed by hydrogen bond network between 1,3,5-tris-(4-carboxyphenyl)benzene (H3BTB) and N,N-dimethylformamide (DMF) and by π–π stacking between the H3BTB moieties. The material can be viewed as a well-ordered array of cages, which are tight packed with each other so that the cages are inaccessible from outside. Thus, the host is practically nonporous. Despite the absence of permanent pathways connecting the empty cages, they are permeable to CO2 at high temperatures due to thermally activated molecular gating, and the weakly confined CO2 molecules in the cages allow direct detection by in situ single-crystal X-ray diffraction at 323 K. Variable-temperature in situ synchrotron powder X-ray diffraction studies also show that the CO2 sorption is reversible and driven by temperature increase. Solid-state magic angle spinning NMR defines the interactions of CO2 with the organic framework and dynamic motion of CO2 in cages. The reversible sorption is attributed to the dynamic motion of the DMF molecules combined with the axial motions/angular fluctuations of CO2 (a series of transient opening/closing of compartments enabling CO2 molecule passage), as revealed from NMR and simulations. This temperature-driven transient molecular gating can store gaseous molecules in ordered arrays toward unique collective properties and release them for ready use.

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Multifunctional magnetic nanoparticles for enhanced intracellular drug transport

Journal of Materials Chemistry B ◽

10.1039/c5tb00547g ◽

2015 ◽

Vol 3 (20) ◽

pp. 4134-4145 ◽

Cited By ~ 13

Author(s):

C. Tudisco ◽

M. T. Cambria ◽

F. Sinatra ◽

F. Bertani ◽

A. Alba ◽

...

Keyword(s):

Magnetic Nanoparticles ◽

Drug Transport ◽

Antitumor Drugs

New multicomponent biocompatible MNPs are designed as intracellular vectors to in situ load antitumor drugs and transport them inside cells.

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DNA Detection Using SiC Nanowire Based Transistor

Materials Science Forum ◽

10.4028/www.scientific.net/msf.858.1006 ◽

2016 ◽

Vol 858 ◽

pp. 1006-1009 ◽

Cited By ~ 2

Author(s):

Edwige Bano ◽

Louis Fradetal ◽

Valérie Stambouli ◽

Giovanni Attolini

Keyword(s):

Silicon Nanowires ◽

Field Effect Transistor ◽

Direct Detection ◽

High Sensitivity ◽

Nanoelectronic Devices ◽

Chemical Inertness ◽

Pathogenic Viruses ◽

Effect Transistor ◽

First Time

The fast and direct detection of small quantities of biomolecules improves early medical diagnosis of certain serious diseases as cancers and can be used to detect in situ the presence of pathogenic viruses or GMOs for food industry, protection environmental and bio-defense. Numerous research projects are conducted on nanoelectronic devices that can perform such detection with high sensitivity using nanostructures. Currently, these devices are made from Silicon nanowires [1]. For these applications, Silicon Carbide (SiC) material can advantageously replace Silicon as this semiconductor is now known to be biocompatible and to show a high chemical inertness [2]. Here, we present the electrical detection of DNA using a SiC Nanowire Field Effect Transistor (NWFET). The NWFETs are fabricated and then functionalized with DNA molecules. Between each step of the functionalization process, I-V characteristic measurements are performed. Comparative and simultaneous measurements are carried out on two SiC NWFETs: one is the sensor and the second one is used as a reference. Some interesting properties of the sensor are studied for the first time which opens the way to future developments of SiC nanowire based sensors.

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