A tristable [2]rotaxane that is doubly gated by foldamer and azobenzene kinetic barriers

2016 ◽  
Vol 52 (47) ◽  
pp. 7490-7493 ◽  
Author(s):  
Wei-Kun Wang ◽  
Zi-Yue Xu ◽  
Yun-Chang Zhang ◽  
Hui Wang ◽  
Dan-Wei Zhang ◽  
...  
Keyword(s):  
Switching System ◽  
System P ◽  
Donor Acceptor ◽  
Kinetic Barriers ◽  
Hydrogen Bonded

Hydrogen bonded foldamer and azobenzene units have been incorporated into a donor–acceptor-type [2]rotaxane to assemble a doubly gated switching system.

scholarly journals Simultaneous determination of parabens and inorganic anions in cosmetics by a two-dimensional ultrahigh-performance liquid chromatography-ion chromatography valve-switching method

RSC Advances ◽  
2017 ◽  
Vol 7 (52) ◽  
pp. 32769-32776 ◽  
Author(s):  
Feng-Lian Wang ◽  
Yong-Gang Zhao ◽  
Nadeem Muhammad ◽  
Shu-Chao Wu ◽  
Yan Zhu
Keyword(s):  
Simultaneous Determination ◽  
Single Injection ◽  
Inorganic Anions ◽  
Two Dimensional ◽  
Switching System ◽  
System P ◽  
Ultrahigh Performance Liquid Chromatography ◽  
Switching Method ◽  
Valve Switching

Simultaneous determination of parabens and inorganic anions in cosmetics in a single injection was obtained in a two-dimensional UHPLC-IC valve switching system.

Donor–acceptor interactions in Friedel–Crafts systems. The CH3COCl•AlCl3 addition compound

1970 ◽  
Vol 48 (24) ◽  
pp. 3860-3871 ◽  
Author(s):  
D. Cassimatis ◽  
J. P. Bonnin ◽  
T. Theophanides
Keyword(s):  
Active Species ◽  
Addition Compound ◽  
Vibrational Assignments ◽  
Carbonyl Band ◽  
Generalized Force ◽  
Donor Acceptor ◽  
Structure Formula ◽  
Limit Form

The infrared spectra of CH3COCl and CH3COCl•AlCl3 have been studied from 4000 to 300 cm−1 with a Perkin–Elmer 621 grating spectrophotometer. The results indicate that the addition compound CH3COCl•AlCl3 exists under three structures, two ionic and one dative structure. The distinct ionic structures are the carbonium type structure [Formula: see text] with a carbonyl band at 2200 cm−1 (type 1) and a structure visualized as a hybrid between resonating structures[Formula: see text]where the mesomeric limit form corresponding to the hyperconjugation is preponderant, with a carbonyl band at 2300 cm−1 (type 2). Vibrational assignments have been made for the two ions and supported by normal coordinate analysis. Two sets of force constants have been derived on the basis of the generalized force field for the two ionic structures to provide a correspondence between observed and calculated frequencies. Evidence would seem to show that the active species in the Friedel–Crafts ketone synthesis is the oxocarbonium type 1 acetylium ion.

scholarly journals Bifunctional Behavior of a Porphyrin in Hydrogen-Bonded Donor–Acceptor Molecular Chains on a Gold Surface

2019 ◽  
Vol 123 (12) ◽  
pp. 7088-7096 ◽  
Author(s):  
Zhijing Feng ◽  
Simone Velari ◽  
Carlo Dri ◽  
Andrea Goldoni ◽  
Laerte L. Patera ◽  
...  
Keyword(s):  
Gold Surface ◽  
Donor Acceptor ◽  
Hydrogen Bonded

Targeting the circadian system

2018 ◽  
Author(s):  
Gregory D. M. Potter ◽  
Eleanor M. Scott
Keyword(s):  
Type 2 Diabetes ◽  
Therapeutic Potential ◽  
System Organization ◽  
Circadian System ◽  
Hierarchical System ◽  
Human Studies ◽  
Metabolic Abnormalities ◽  
System P ◽  
Key Aspects

Circadian (approximately 24-hour) rhythms are generated by a hierarchical system responsible for coordinating behaviour and physiology throughout the 24-hour day. Increasing evidence supports roles for disruption of the circadian system in the development of type 2 diabetes (T2DM) and depression. We outline the key aspects of circadian system regulation, discuss the findings indicating that biological disruption of the circadian system produces various behavioural and metabolic abnormalities, and review human studies which show that environmental disruption of the circadian system contributes to T2DM and depression. Finally, we will summarize the therapeutic potential of restoring circadian system organization to manage these diseases.

Therapy-related issues: endocrine system

2012 ◽  
Author(s):  
Philip Wiffen ◽  
Marc Mitchell ◽  
Melanie Snelling ◽  
Nicola Stoner
Keyword(s):  
Diabetes Mellitus ◽  
Endocrine System ◽  
Monitoring And Control ◽  
Cell Dysfunction ◽  
System P ◽  
The Uk ◽  
P Type ◽  
And Control

Diabetes mellitus 444Monitoring and control 449Thyroid disorders 450Diabetes mellitus (DM) affects approximately 4% of the UK population. In 2009, Diabetes UK reported that 2.6 million people in the UK have diabetes.Type 2 diabetes accounts for 90% of all diabetes and is a result of insulin resistance and pancreatic β-cell dysfunction. Type 1 diabetes results from an absolute insulin deficiency secondary to autoimmune dysfunction....

scholarly journals Proton transfer in hydrogen-bonded degenerate systems of water and ammonia in metal–organic frameworks

2019 ◽  
Vol 10 (1) ◽  
pp. 16-33 ◽  
Author(s):  
Dae-Woon Lim ◽  
Masaaki Sadakiyo ◽  
Hiroshi Kitagawa
Keyword(s):  
Proton Transfer ◽  
Metal Organic Frameworks ◽  
Proton Conductors ◽  
Degenerate System ◽  
New Class ◽  
System P ◽  
Metal Organic ◽  
Crystalline Metal ◽  
Hydrogen Bonded

Porous crystalline metal–organic frameworks (MOFs) are emerging as a new class of proton conductors through the hydrogen-bonded degenerate system.

scholarly journals Large-scale synthesis of carbon dots/TiO2 nanocomposites for the photocatalytic color switching system

2019 ◽  
Vol 1 (5) ◽  
pp. 1819-1825 ◽  
Author(s):  
Aiwu Wang ◽  
Xufen Xiao ◽  
Cangtao Zhou ◽  
Fucong Lyu ◽  
Li Fu ◽  
...  
Keyword(s):  
Carbon Dots ◽  
Large Scale ◽  
Switching System ◽  
System P ◽  
Large Scale Synthesis ◽  
Color Switching

In view of the easy control and contactless spatial nature of light, the photoreversible color switching system has attracted tremendous attention.

Molecular recognition XI. The synthesis of extensively deoxygenated derivatives of the H-type 2 human blood group determinant and their binding by an anti-H-type 2 monoclonal antibody and the lectin 1 of Ulexeuropaeus

1992 ◽  
Vol 70 (1) ◽  
pp. 254-271 ◽  
Author(s):  
Ulrike Spohr ◽  
Eugenia Paszkiewicz-Hnatiw ◽  
Naohiko Morishima ◽  
Raymond U. Lemieux
Keyword(s):  
Monoclonal Antibody ◽  
Molecular Recognition ◽  
Blood Group ◽  
Human Blood ◽  
Water Molecules ◽  
Hydroxyl Groups ◽  
Human Blood Group ◽  
Derivatives Of ◽  
Hydrogen Bonded

The relative potencies of a wide variety of deoxygenated derivatives of the methyl glycoside of α-L-Fuc-(1 → 2)-β-D-Gal-(1 → 4)- β-D-GlcNAc (the H-type 2 human blood group related trisaccharide) for the inhibition of the binding of an artificial H-type 2 antigen by the lectin I of Ulexeuropaeus confirmed the previous evidence that the key and productive interaction involves only the three hydroxyl groups of the α-L-fucose unit, the hydroxyl at the 3-position of the β-D-galactose residue, and the nonpolar groups in their immediate environment. Except for the acetamido group and the hydroxymethyl of the β-D-Gal unit, which stay in the aqueous phase, on complex formation the remaining three hydroxyl groups appear to come to reside at or near the periphery of the combining site since their replacement by hydrogen causes relatively small changes (< ± 1 kcal/mol) in the stability of the complex (ΔG0). Relatively much larger but compensating changes occur for the enthalpy and entropy terms, and these may arise primarily from the differences in the water structure about the periphery of the combining site and the oligosaccharide both prior to and after complexation. It is proposed that steric constraints lead to an ordered state of the water molecules hydrogen-bonded to the polar groups within the cleft formed by the key region of the amphiphilic combining site. Their release to form less ordered clusters of more strongly hydrogen-bonded water molecules in bulk solution would contribute importantly to the driving force for complexation. It is demonstrated that the surface used for the binding of H-type 2-OMe by a monoclonal anti-H antibody is virtually identical to that used by the Ulex lectin. Keywords: molecular recognition, H-type 2 blood group determinant and deoxygenated derivatives, lectin I of Ulexeuropaeus, anti-H-type 2 monoclonal antibody, enthalpy–entropy compensation.

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