Extended nanospace chemical systems on a chip for new analytical technology

The Analyst ◽  
2011 ◽  
Vol 136 (15) ◽  
pp. 3051 ◽  
Author(s):  
Kazuma Mawatari ◽  
Takehiko Tsukahara ◽  
Takehiko Kitamori
Keyword(s):  
Chemical Systems ◽  
Extended Nanospace ◽  
Analytical Technology

Thermodynamics of Chemical Systems

1990 ◽  
Author(s):  
Scott Emerson Wood ◽  
Rubin Battino
Keyword(s):  
Chemical Systems

Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley
Keyword(s):  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Chemical Systems ◽  
Complex Architectures ◽  
The Creation ◽  
Dynamic Exchange

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

Chemically Fueled Assembly of Macrocycles Comprising Multiple Transient Bonds

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley
Keyword(s):  
Covalent Bond ◽  
Dicarboxylic Acids ◽  
Molecular Assembly ◽  
Chemical Systems ◽  
Complex Architectures ◽  
The Creation ◽  
Dynamic Exchange

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

Nanocrystals: The Preparation, Precise Control and Application Toward the Pharmaceutics and Food Industry

2018 ◽  
Vol 24 (21) ◽  
pp. 2425-2431 ◽  
Author(s):  
Cao Wu ◽  
Zhou Chen ◽  
Ya Hu ◽  
Zhiyuan Rao ◽  
Wangping Wu ◽  
...  
Keyword(s):  
Food Industry ◽  
Chemical Properties ◽  
Preparation Methods ◽  
Precise Control ◽  
Significant Process ◽  
Technology Applications ◽  
And Performance ◽  
Physical And Chemical ◽  
Analytical Technology ◽  
And Chemical Properties

Crystallization is a significant process employed to produce a wide variety of materials in pharmaceutical and food area. The control of crystal dimension, crystallinity, and shape is very important because they will affect the subsequent filtration, drying and grinding performance as well as the physical and chemical properties of the material. This review summarizes the special features of crystallization technology and the preparation methods of nanocrystals, and discusses analytical technology which is used to control crystal quality and performance. The crystallization technology applications in pharmaceutics and foods are also outlined. These illustrated examples further help us to gain a better understanding of the crystallization technology for pharmaceutics and foods.

Structure and Activity of Pentacyclic Triterpenes Codrugs. A Review

2021 ◽  
Vol 21 ◽  
Author(s):  
Justyna Żwawiak ◽  
Anna Pawełczyk ◽  
Dorota Olender ◽  
Lucjusz Zaprutko
Keyword(s):  
Biological Activities ◽  
Anticancer Activities ◽  
Drug Molecule ◽  
Pentacyclic Triterpene ◽  
Formation Pathway ◽  
Chemical Systems ◽  
Drug Molecules ◽  
Wide Range ◽  
Anti Hiv ◽  
Structure And Activity

: Triterpenes are a wide and important group of compounds that have several promising pharmacological properties, such as hepatoprotective, anti-inflammatory, anti-HIV, antioxidant, or anticancer activities. Such potent substances can be successfully incorporated in more complex chemical systems e.g. codrugs or pro-drugs that have better pharmacological profile. The codrug is connected with a drug formation pathway to chemically cohere at least two drug molecules to improve positive therapeutic efficiency or decrease side effects. The codrug can be cleaved in the organism to generate effective compounds previously used as substrates. This article presents an overview of codrugs that consist of pentacyclic triterpene moiety that is chosen as a basic codrug moiety due to their wide range of vital activities and another drug molecule fragment. It was found that triterpenoid codrugs are characterized by a wide range of biological activities. However, most of them have anticancer potency.

Introductory Rotational Dynamics

2018 ◽  
Author(s):  
Peter Mann
Keyword(s):  
Angular Momentum ◽  
Angular Displacement ◽  
Rigid Bodies ◽  
Rotational Dynamics ◽  
Circular Motion ◽  
Uniform Rotation ◽  
Chemical Systems ◽  
Inertial Frames ◽  
Rotating Frames ◽  
Special Case

This chapter discusses the importance of circular motion and rotations, whose applications to chemical systems are plentiful. Circular motion is the book’s first example of a special case of motion using the laws developed in previous chapters. The chapter begins with the basic definitions of circular motion; as uniform rotation around a principle axis is much easier to consider, it is the focus of this chapter and is used to develop some key ideas. The chapter discusses angular displacement, angular velocity, angular momentum, torque, rigid bodies, orbital and spin momenta, inertia tensors and non-inertial frames and explores fictitious forces as well as transformations in rotating frames.

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