Supramolecular complexes formed by dimethoxypillar[5]arenes and imidazolium salts: a joint experimental and computational investigation

2017 ◽  
Vol 41 (21) ◽  
pp. 12490-12505
Author(s):  
Francesca D'Anna ◽  
Carla Rizzo ◽  
Paola Vitale ◽  
Salvatore Marullo ◽  
Francesco Ferrante
Keyword(s):  
Structural Features ◽  
Supramolecular Complexes ◽  
Combined Approach ◽  
Imidazolium Salts ◽  
Computational Investigation ◽  
The Stability

The stability of host–guest complexes formed by dimethoxypillar[5]arenes and imidazolium salts has been analyzed as a function of different structural features of the guest, using a combined approach of different techniques.

FABRICATION OF NANOPOROUS CHITOSAN MEMBRANES

NANO ◽  
2010 ◽  
Vol 05 (01) ◽  
pp. 53-60 ◽  
Author(s):  
XIAOLIANG WANG ◽  
XIANG LI ◽  
ELEANOR STRIDE ◽  
MOHAN EDIRISINGHE
Keyword(s):  
Low Frequency ◽  
Drug Carriers ◽  
Structural Features ◽  
Wound Dressings ◽  
Ftir Analysis ◽  
Tissue Engineering Scaffolds ◽  
Nanoscale Structures ◽  
Low Frequency Ultrasound ◽  
Chitosan Membranes ◽  
The Stability

Naturally derived biopolymers have been widely used for biomedical applications such as drug carriers, wound dressings, and tissue engineering scaffolds. Chitosan is a typical polysaccharide of great interest due to its biocompatibility and film-formability. Chitosan membranes with controllable porous structures also have significant potential in membrane chromatography. Thus, the processing of membranes with porous nanoscale structures is of great importance, but it is also challenging and this has limited the application of these membranes to date. In this study, with the aid of a carefully selected surfactant, polyethyleneglycol stearate-40, chitosan membranes with a well controlled nanoscale structure were successfully prepared. Additional control over the membrane structure was obtained by exposing the suspension to high intensity, low frequency ultrasound. It was found that the concentration of chitosan/surfactant ratio and the ultrasound exposure conditions affect the structural features of the membranes. The stability of nanopores in the membrane was improved by intensive ultrasonication. Furthermore, the stability of the blended suspensions and the intermolecular interactions between chitosan and the surfactant were investigated using scanning electron microscope and Fourier transform infrared spectroscopy (FTIR) analysis, respectively. Hydrogen bonds and possible reaction sites for molecular interactions in the two polymers were also confirmed by FTIR analysis.

scholarly journals Exploiting directional long range secondary forces for regulating electrostatics-dominated noncovalent interactions

2017 ◽  
Vol 8 (2) ◽  
pp. 1378-1390 ◽  
Author(s):  
Mrityunjay K. Tiwari ◽  
Kumar Vanka
Keyword(s):  
Long Range ◽  
Electrostatic Interactions ◽  
Noncovalent Interactions ◽  
Supramolecular Complexes ◽  
The Stability

It has been well established that long range secondary electrostatic interactions (SEIs) have a significant effect on the stability of supramolecular complexes.

scholarly journals Surface-Tension-Confined Channel with Biomimetic Microstructures for Unidirectional Liquid Spreading

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 978
Author(s):  
Yi Zhang ◽  
Yang Gan ◽  
Liwen Zhang ◽  
Deyuan Zhang ◽  
Huawei Chen
Keyword(s):  
Surface Tension ◽  
Underlying Mechanism ◽  
Structural Features ◽  
Liquid Motion ◽  
Water Separation ◽  
Lab On Chip ◽  
Liquid Spreading ◽  
Oil Water Separation ◽  
On Chip ◽  
The Stability

Unidirectional liquid spreading without energy input is of significant interest for the broad applications in diverse fields such as water harvesting, drop transfer, oil–water separation and microfluidic devices. However, the controllability of liquid motion and the simplification of manufacturing process remain challenges. Inspired by the peristome of Nepenthes alata, a surface-tension-confined (STC) channel with biomimetic microcavities was fabricated facilely through UV exposure photolithography and partial plasma treatment. Perfect asymmetric liquid spreading was achieved by combination of microcavities and hydrophobic boundary, and the stability of pinning effect was demonstrated. The influences of structural features of microcavities on both liquid spreading and liquid pinning were investigated and the underlying mechanism was revealed. We also demonstrated the spontaneous unidirectional transport of liquid in 3D space and on tilting slope. In addition, through changing pits arrangement and wettability pattern, complex liquid motion paths and microreactors were realized. This work will open a new way for liquid manipulation and lab-on-chip applications.

Crystallographic analysis and biochemical applications of a novel penicillin-binding protein/β-lactamase homologue from a metagenomic library

2014 ◽  
Vol 70 (9) ◽  
pp. 2455-2466 ◽  
Author(s):  
Tri Duc Ngo ◽  
Bum Han Ryu ◽  
Hansol Ju ◽  
Eun Jin Jang ◽  
Kyeong Kyu Kim ◽  
...  
Keyword(s):  
Metagenomic Library ◽  
Structural Features ◽  
Crystallographic Analysis ◽  
Penicillin Binding Protein ◽  
Hydrophobic Residues ◽  
Penicillin Binding Proteins ◽  
Hydrophobic Compounds ◽  
Nitrophenyl Phosphate ◽  
Biophysical Studies ◽  
The Stability

Interest in penicillin-binding proteins and β-lactamases (the PBP-βL family) is increasing owing to their biological and clinical significance. In this study, the crystal structure of Est-Y29, a metagenomic homologue of the PBP-βL family, was determined at 1.7 Å resolution. In addition, complex structures of Est-Y29 with 4-nitrophenyl phosphate (4NP) and with diethyl phosphonate (DEP) at 2.0 Å resolution were also elucidated. Structural analyses showed that Est-Y29 is composed of two domains: a β-lactamase fold and an insertion domain. A deep hydrophobic patch between these domains defines a wide active site, and a nucleophilic serine (Ser58) residue is located in a groove defined primarily by hydrophobic residues between the two domains. In addition, three hydrophobic motifs, which make up the substrate-binding site, allow this enzyme to hydrolyze a wide variety of hydrophobic compounds, including fish and olive oils. Furthermore, cross-linked Est-Y29 aggregates (CLEA-Est-Y29) significantly increase the stability of the enzyme as well as its potential for extensive reuse in various deactivating conditions. The structural features of Est-Y29, together with biochemical and biophysical studies, could provide a molecular basis for understanding the properties and regulatory mechanisms of the PBP-βL family and their potential for use in industrial biocatalysts.

scholarly journals Joint crystallization of KCuAl[PO4]2 and K(Al,Zn)2[(P,Si)O4]2: crystal chemistry and mechanism of formation of phosphate-silicate epitaxial heterostructure

2020 ◽  
Vol 76 (3) ◽  
pp. 483-491
Author(s):  
Olga Yakubovich ◽  
Galina Kiriukhina ◽  
Larisa Shvanskaya ◽  
Anatoliy Volkov ◽  
Olga Dimitrova
Keyword(s):  
Crystal Structures ◽  
Active Material ◽  
Structure Type ◽  
Structural Features ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrochemically Active ◽  
Phosphate Silicate ◽  
The Stability ◽  
Small Channels

Two novel phases, potassium copper aluminium bis(phosphate), KCuAl[PO4]2 (I), and potassium zinc aluminium bis(phosphate-silicate), K(Al,Zn)2[(P,Si)O4]2 (II), were obtained in one hydrothermal synthesis experiment at 553 K. Their crystal structures have been studied using single-crystal X-ray diffraction. (I) is a new member of the A + M 2+ M 3+[PO4]2 family. Its open 3D framework built by AlO5 and PO4 polyhedra includes small channels populated by columns of CuO6 octahedra sharing edges, and large channels where K+ ions are deposited. It is assumed that the stability of this structure type is due to the pair substitution of Cu/Al with Ni/Fe, Co/Fe or Mg/Fe in different representatives of the series. From the KCuAl[PO4]2 structural features, one may suppose it is a potentially electrochemically active material and/or possible low-temperature antiferromagnet. In accordance with results obtained from X-ray diffraction data, using scanning electron microscopy, microprobe analysis and detailed crystal chemical observation, (II) is considered as a product of epitaxial intergrowth of phosphate KAlZn[PO4]2 and silicate KAlSi[SiO4]2 components having closely similar crystal structures. The assembly of `coherent intergrowth' is described in the framework of a single diffraction pattern.

scholarly journals Computational investigation of the stability and dissolution of nanobubbles

2017 ◽  
Vol 49 ◽  
pp. 199-219 ◽  
Author(s):  
Knut Sverdrup ◽  
Sven-Joachim Kimmerle ◽  
Peter Berg
Keyword(s):  
Computational Investigation ◽  
The Stability

Shapes of supramolecular cages by ion mobility mass spectrometry

2012 ◽  
Vol 48 (37) ◽  
pp. 4423-4425 ◽  
Author(s):  
Jakub Ujma ◽  
Martin De Cecco ◽  
Oleg Chepelin ◽  
Hannah Levene ◽  
Chris Moffat ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Mobility ◽  
Supramolecular Complexes ◽  
Ion Mobility Mass Spectrometry ◽  
Structural Differences ◽  
Self Assembled ◽  
The Stability

Ion mobility mass spectrometry distinguishes between isobaric supramolecular complexes, revealing subtle structural differences and their effect on the stability of self assembled architectures.

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