Impact of chemistry on the preparation and post-modification of multilayered hollow microcapsules

2021 ◽  
Author(s):  
Angana Borbora ◽  
Uttam Manna
Keyword(s):  
Chemical Interactions ◽  
Chemical Modifications ◽  
Post Modification

Different chemical interactions/bonding allowed LbL deposition of selected constituents, and further post-chemical modifications of chemically reactive multilayered microcapsules allowed to associate desired chemical functionalities.

TLC detection of chemical interactions of vitamins A and D with drugs

2006 ◽  
Vol 19 (107) ◽  
pp. 27-31 ◽  
Author(s):  
Alan Ramić ◽  
Marica Medić-Šarić ◽  
Srećko Turina ◽  
Ivona Jasprica
Keyword(s):  
Chemical Interactions

SuFExable Polymers with Helical Structures Derived from Thionyl Tetrafluoride (SOF4)

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  
Keyword(s):  
Functional Polymers ◽  
Polymer Chains ◽  
New Materials ◽  
Helical Structures ◽  
Polymer Backbone ◽  
Silyl Ethers ◽  
Helical Polymer ◽  
Key Characteristics ◽  
Post Modification ◽  
Individual Polymer

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.

Degradation Analysis of Thick Film Chip Resistors

2009 ◽  
Author(s):  
Bhanu Sood ◽  
Diganta Das ◽  
Michael H. Azarian ◽  
Michael Pecht
Keyword(s):  
Thick Film ◽  
Printed Circuit Board ◽  
Negative Resistance ◽  
Circuit Board ◽  
High Humidity ◽  
Circuit Boards ◽  
Chemical Modifications ◽  
Current Leakage ◽  
Printed Circuit ◽  
Degradation Analysis

Abstract Negative resistance drift in thick film chip resistors in high temperature and high humidity application conditions was investigated. This paper reports on the investigation of possible causes including formation of current leakage paths on the printed circuit board, delamination between the resistor protective coating and laser trim, and the possibility of silver migration or copper dendrite formation. Analysis was performed on a set of circuit boards exhibiting failures due to this phenomenon. Electrical tests after mechanical and chemical modifications showed that the drift was most likely caused by moisture ingress that created a conductive path across the laser trim.

On physico-chemical interactions between daunomycin and nucleic acids

1965 ◽  
Vol 103 (1) ◽  
pp. 25-49 ◽  
Author(s):  
E. Calendi ◽  
A. Di Marco ◽  
M. Reggiani ◽  
B. Scarpinato ◽  
L. Valentini
Keyword(s):  
Nucleic Acids ◽  
Chemical Interactions ◽  
Physico Chemical

scholarly journals Rational Generation of Lasso Peptides Based on Biosynthetic Gene Mutations and Site-Selective Chemical Modifications

2021 ◽  
Author(s):  
Tan Liu ◽  
Xiaojie Ma ◽  
Jiahui Yu ◽  
Wensheng Yang ◽  
guiyang wang ◽  
...  
Keyword(s):  
Natural Products ◽  
Gene Mutations ◽  
Proteolytic Degradation ◽  
Biosynthetic Gene ◽  
Chemical Modifications ◽  
Lasso Peptides ◽  
Selective Chemical ◽  
Site Selective

Lasso peptides are a unique family of natural products whose structures feature a specific threaded fold, which confers these peptides the resistance to thermal and proteolytic degradation. This stability gives...

scholarly journals Thiophene-Based Trimers and Their Bioapplications: An Overview

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1977
Author(s):  
Lorenzo Vallan ◽  
Emin Istif ◽  
I. Jénnifer Gómez ◽  
Nuria Alegret ◽  
Daniele Mantione
Keyword(s):  
Optical Properties ◽  
Medical Research ◽  
Turning Point ◽  
State Of The Art ◽  
Thiophene Ring ◽  
Functional Polymers ◽  
Direct Application ◽  
Synthetic Methods ◽  
Scientific Interest ◽  
Chemical Modifications

Certainly, the success of polythiophenes is due in the first place to their outstanding electronic properties and superior processability. Nevertheless, there are additional reasons that contribute to arouse the scientific interest around these materials. Among these, the large variety of chemical modifications that is possible to perform on the thiophene ring is a precious aspect. In particular, a turning point was marked by the diffusion of synthetic strategies for the preparation of terthiophenes: the vast richness of approaches today available for the easy customization of these structures allows the finetuning of their chemical, physical, and optical properties. Therefore, terthiophene derivatives have become an extremely versatile class of compounds both for direct application or for the preparation of electronic functional polymers. Moreover, their biocompatibility and ease of functionalization make them appealing for biology and medical research, as it testifies to the blossoming of studies in these fields in which they are involved. It is thus with the willingness to guide the reader through all the possibilities offered by these structures that this review elucidates the synthetic methods and describes the full chemical variety of terthiophenes and their derivatives. In the final part, an in-depth presentation of their numerous bioapplications intends to provide a complete picture of the state of the art.

scholarly journals Antiviral Activity of Carrageenans and Processing Implications

Marine Drugs ◽  
2021 ◽  
Vol 19 (8) ◽  
pp. 437
Author(s):  
Milena Álvarez-Viñas ◽  
Sandra Souto ◽  
Noelia Flórez-Fernández ◽  
Maria Dolores Torres ◽  
Isabel Bandín ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Antiviral Activity ◽  
Drug Delivery Systems ◽  
Biological Properties ◽  
Red Seaweed ◽  
Processing Conditions ◽  
Chemical Modifications ◽  
Viral Attachment ◽  
Extraction Stage ◽  
Composition Structure

Carrageenan and carrageenan oligosaccharides are red seaweed sulfated carbohydrates with well-known antiviral properties, mainly through the blocking of the viral attachment stage. They also exhibit other interesting biological properties and can be used to prepare different drug delivery systems for controlled administration. The most active forms are λ-, ι-, and κ-carrageenans, the degree and sulfation position being determined in their properties. They can be obtained from sustainable worldwide available resources and the influence of manufacturing on composition, structure, and antiviral properties should be considered. This review presents a survey of the antiviral properties of carrageenan in relation to the processing conditions, particularly those assisted by intensification technologies during the extraction stage, and discusses the possibility of further chemical modifications.

scholarly journals Tripeptide Self-Assembly into Bioactive Hydrogels: Effects of Terminus Modification on Biocatalysis

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 173
Author(s):  
Marina Kurbasic ◽  
Ana M. Garcia ◽  
Simone Viada ◽  
Silvia Marchesan
Keyword(s):  
Self Assembly ◽  
The Self ◽  
Chemical Modifications ◽  
Ability To Work ◽  
Active Compounds ◽  
Future Design ◽  
Self Organized ◽  
The Future ◽  
Bio Material ◽  
Supramolecular Catalysts

Bioactive hydrogels based on the self-assembly of tripeptides have attracted great interest in recent years. In particular, the search is active for sequences that are able to mimic enzymes when they are self-organized in a nanostructured hydrogel, so as to provide a smart catalytic (bio)material whose activity can be switched on/off with assembly/disassembly. Within the diverse enzymes that have been targeted for mimicry, hydrolases find wide application in biomaterials, ranging from their use to convert prodrugs into active compounds to their ability to work in reverse and catalyze a plethora of reactions. We recently reported the minimalistic l-His–d-Phe–d-Phe for its ability to self-organize into thermoreversible and biocatalytic hydrogels for esterase mimicry. In this work, we analyze the effects of terminus modifications that mimic the inclusion of the tripeptide in a longer sequence. Therefore, three analogues, i.e., N-acetylated, C-amidated, or both, were synthesized, purified, characterized by several techniques, and probed for self-assembly, hydrogelation, and esterase-like biocatalysis. This work provides useful insights into how chemical modifications at the termini affect self-assembly into biocatalytic hydrogels, and these data may become useful for the future design of supramolecular catalysts for enhanced performance.

Sign in / Sign up

Export Citation Format

Share Document