scholarly journals Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test

2014 ◽  
Vol 10 ◽  
pp. 2729-2737 ◽  
Author(s):  
Gerald Jarre ◽  
Steffen Heyer ◽  
Elisabeth Memmel ◽  
Thomas Meinhardt ◽  
Anke Krueger
Keyword(s):  
Diels Alder ◽  
Amino Groups ◽  
Pyrimidine Derivatives ◽  
Quantification Method ◽  
Different Types ◽  
Primary Amino ◽  
Wet Chemical ◽  
Terminal Amino ◽  
Chemical Quantification

Nanodiamonds functionalized with different organic moieties carrying terminal amino groups have been synthesized. These include conjugates generated by Diels–Alder reactions of ortho-quinodimethanes formed in situ from pyrazine and 5,6-dihydrocyclobuta[d]pyrimidine derivatives. For the quantification of primary amino groups a modified photometric assay based on the Kaiser test has been developed and validated for different types of aminated nanodiamond. The results correspond well to values obtained by thermogravimetry. The method represents an alternative wet-chemical quantification method in cases where other techniques like elemental analysis fail due to unfavourable combustion behaviour of the analyte or other impediments.

Model Compound Approach for Polymer-Metal InterFaces: ESCA Studies

1984 ◽  
Vol 40 ◽  
Author(s):  
P. N. Sanda ◽  
J. W. Bartha ◽  
B. D. Silverman ◽  
P. S. Ho ◽  
A. R. Rossi
Keyword(s):  
Model Compound ◽  
Amino Groups ◽  
Ether Linkage ◽  
Cu Films ◽  
Polymer Metal ◽  
Terminal Amino ◽  
Metal Interfaces ◽  
Imide Group

AbstractESCA studies of two molecules which are similar in structure to the PMDA and ODA constituents of the PMDA-ODA polyimide monomer are discussed. Their interaction with in-situ evaporated Cr and Cu films are compared. The PMDA model compound interacts with Cr through the imide group, while very little interaction is observed with Cu. The ODA model compound (oxydianiline) interacts with Cr via the ether linkage and the terminal amino groups, whereas very little interaction is observed with Cu.

Characterization of organic monolayers on individual microparticles using microprobe mass spectrometry

1992 ◽  
Vol 50 (2) ◽  
pp. 1710-1711
Author(s):  
Thomas Fister ◽  
John Chakel ◽  
Robert Odom ◽  
Filippo Radicati di Brozolo ◽  
Richard W. Linton
Keyword(s):  
Mass Spectrometry ◽  
Fossil Fuels ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Transformations ◽  
Organic Monolayers ◽  
Different Types ◽  
Wet Chemical ◽  
Secondary Ion

Polycyclic organic matter (POM) represents a class of compounds of environmental significance. Many of these compounds have been shown to exhibit mutagenic characteristics. POM is formed during the combustion of fossil fuels such as coal. Emitted particulate matter such as coal flyash contains surface associated POM that undergoes chemical transformations due to photolysis and exposure to gaseous pollutants. Past studies of these compounds on flyash have relied on wet chemical techniques in which POM is extracted from large quantities of flyash and then analyzed by chromatography. This technique is hindered by several problems such as the extensive heterogeneity in flyash composition. Individual flyash particles of different composition will influence POM adsorption and reactivity. Studies of the different types of particles by the wet techniques require that the particles be physically separated (density, size, magnetic properties). Microprobe secondary ion mass spectrometry (SIMS) is a technique that can potentially overcome these obstacles by permitting the in situ analysis of POM on single particle surfaces.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

Pb Electrodeposition in the Presence of Chlorine Ions on Cu(100): An in Situ Optical Reflectivity Difference Study

2003 ◽  
Vol 781 ◽  
Author(s):  
J. Gray ◽  
W. Schwarzacher ◽  
X.D. Zhu
Keyword(s):  
Oblique Incidence ◽  
Opposite Sign ◽  
Bulk Phase ◽  
Phase Layer ◽  
Optical Reflectivity ◽  
Scan Rate ◽  
Different Types ◽  
Chlorine Ions ◽  
High Overpotentials

AbstractWe studied the initial stages of the electrodeposition of Pb in the presence of chlorine ions on Cu(100), using an oblique-incidence optical reflectivity difference (OIRD) technique. The OI-RD results reveal that immediately following the underpotential deposition (UPD) of the first Pb monolayer, two different types of bulk-phase films grow depending upon the magnitude of overpotential and cyclic voltammetry (CV) scan rate. At low overpotentials and/or slow scan rates, we propose that a bulk-phase Pb film grows on top of the UPD monolayer. At high overpotentials and/or fast scan rates, either a PbO, PbCl2, or a rough Pb bulk-phase layer grows on top of the UPD layer such that the reflectivity difference signal from such a film has an opposite sign.

Purification of Penicillin Amidohydrolase, an Enzyme for Semisynthetic Procedures

1992 ◽  
Vol 57 (10) ◽  
pp. 2187-2191 ◽  
Author(s):  
Jiří Jiráček ◽  
Tomislav Barth ◽  
Jiří Velek ◽  
Ivo Bláha ◽  
Jan Pospíšek ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Amino Groups ◽  
Primary Amino

Penicillin amidohydrolase (EC 3.5.1.11.) is one of the few enzymes used successfully for deprotection of primary amino groups of semisynthetic peptides. The available material is usually contamined by endo- and exopeptidases. We managed to prepare the enzyme devoid of trypsin- and chymotrypsin-like activities using affinity chromatography with specific ligands: Gly-D-Phe-Phe-Tyr-Thr-Pro-Lys-Thr (the fF peptide) and Leu-Gly-Val-D-Arg-Arg-Gly-Phe (the rR peptide). For further purification of the enzyme affinity chromatography with N-phenylacetyl-D-tert-Leu as a ligand was used.

Coupling of Steroid O-(Carboxymethyl)oxime Derivatives with Single-Protected α,ω-Diaminoalkanes

1999 ◽  
Vol 64 (12) ◽  
pp. 2035-2043 ◽  
Author(s):  
Vladimír Pouzar ◽  
Ivan Černý ◽  
Pavel Drašar
Keyword(s):  
Trifluoroacetic Acid ◽  
Protecting Groups ◽  
Oxime Group ◽  
Amino Groups ◽  
New Approach ◽  
Terminal Amino ◽  
Oxime Derivatives

New approach to the synthesis of steroid oximes bearing O-substituents with terminal amino groups was described. The easily accessible steroid O-(carboxymethyl)oximes were reacted with single-protected Boc-α,ω-diaminoalkanes to give corresponding amide intermediates. From them the Boc protecting groups were cleaved with trifluoroacetic acid to afford the desired steroid derivatives with terminal amino groups. The procedure was succesfully tested on steroids with O-(carboxymethyl)oxime group in positions 7 and 17. The decomposition of target products was observed during deprotection of substituted 19-oximes.

scholarly journals In Situ Study of the Wet Chemical Etching of SiO2 and Nanoparticle@SiO2 Core–Shell Nanospheres

2021 ◽  
Author(s):  
Albert Grau-Carbonell ◽  
Sina Sadighikia ◽  
Tom A. J. Welling ◽  
Relinde J. A. van Dijk-Moes ◽  
Ramakrishna Kotni ◽  
...  
Keyword(s):  
Chemical Etching ◽  
Core Shell ◽  
In Situ Study ◽  
Wet Chemical ◽  
Wet Chemical Etching

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.

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