scholarly journals Surface interaction of WO3 nanocrystals with NH3. Role of the exposed crystal surfaces and porous structure in enhancing the electrical response

RSC Advances ◽  
2014 ◽  
Vol 4 (22) ◽  
pp. 11012 ◽  
Author(s):  
Massimiliano D'Arienzo ◽  
Lidia Armelao ◽  
Claudio Maria Mari ◽  
Stefano Polizzi ◽  
Riccardo Ruffo ◽  
...  
Keyword(s):  
Porous Structure ◽  
Electrical Response ◽  
Surface Interaction ◽  
Crystal Surfaces

Fabrication of poly (1, 8-octanediol-co-Pluronic F127 citrate)/chitin nanofibril/bioactive glass (POFC/ChiNF/BG) porous scaffold via directional-freeze-casting

2020 ◽  
Vol 40 (7) ◽  
pp. 591-599
Author(s):  
Yaling Tian ◽  
Kai Liang ◽  
Yali Ji
Keyword(s):  
Bioactive Glass ◽  
Porous Structure ◽  
Pore Structure ◽  
Porous Scaffold ◽  
Pluronic F127 ◽  
Porous Scaffolds ◽  
Freeze Casting ◽  
Promising Candidate ◽  
Complete Replacement

AbstractThe citrate-based thermoset elastomer is a promising candidate for bone scaffold material, but the harsh curing condition made it difficult to fabricate porous structure. Recently, poly (1, 8-octanediol-co-Pluronic F127 citrate) (POFC) porous scaffold was creatively fabricated by chitin nanofibrils (ChiNFs) supported emulsion-freeze-casting. Thanks to the supporting role of ChiNFs, the lamellar pore structure formed by directional freeze-drying was maintained during the subsequent thermocuring. Herein, bioactive glass (BG) was introduced into the POFC porous scaffolds to improve bioactivity. It was found the complete replacement of ChiNF particles with BG particles could not form a stable porous structure; however, existing at least 15 wt% ChiNF could ensure the formation of lamellar pore, and the interlamellar distance increased with BG ratios. Thus, the BG granules did not contribute to the formation of pore structure like ChiNFs, however, they surely endowed the scaffolds with enhanced mechanical properties, improved osteogenesis bioactivity, better cytocompatibility as well as quick degradation rate. Reasonably adjusting BG ratios could balance the requirements of porous structure and bioactivity.

Molecular modulation of calcium oxalate crystallization

2006 ◽  
Vol 291 (6) ◽  
pp. F1123-F1132 ◽  
Author(s):  
James J. De Yoreo ◽  
S. Roger Qiu ◽  
John R. Hoyer
Keyword(s):  
Molecular Modeling ◽  
Calcium Oxalate ◽  
Stone Formation ◽  
Energy Levels ◽  
Critical Role ◽  
Specific Interactions ◽  
Crystal Surfaces ◽  
Site Specific

Calcium oxalate monohydrate (COM) is the primary constituent of the majority of renal stones. Osteopontin (OPN), an aspartic acid-rich urinary protein, and citrate, a much smaller molecule, are potent inhibitors of COM crystallization at levels present in normal urine. Current concepts of the role of site-specific interactions in crystallization derived from studies of biomineralization are reviewed to provide a context for understanding modulation of COM growth at a molecular level. Results from in situ atomic force microscopy (AFM) analyses of the effects of citrate and OPN on growth verified the critical role of site-specific interactions between these growth modulators and individual steps on COM crystal surfaces. Molecular modeling investigations of interactions of citrate with steps and faces on COM crystal surfaces provided links between the stereochemistry of interaction and the binding energy levels that underlie mechanisms of growth modification and changes in overall crystal morphology. The combination of in situ AFM and molecular modeling provides new knowledge that will aid rationale design of therapeutic agents for inhibition of stone formation.

scholarly journals Role of nanostructured polymers on the improvement of electrical response-based relative humidity sensors

2016 ◽  
Vol 225 ◽  
pp. 96-108 ◽  
Author(s):  
I. Fratoddi ◽  
A. Bearzotti ◽  
I. Venditti ◽  
C. Cametti ◽  
M.V. Russo
Keyword(s):  
Relative Humidity ◽  
Electrical Response ◽  
Nanostructured Polymers ◽  
Humidity Sensors

Study of the Water-Glass Role in the Foam Glass Synthesis Using Glycerol Foaming Agent

2021 ◽  
Vol 316 ◽  
pp. 153-158
Author(s):  
Boris M. Goltsman ◽  
Lyubov A. Yatsenko ◽  
Natalia S. Goltsman
Keyword(s):  
Porous Structure ◽  
Structure Formation ◽  
Water Glass ◽  
Glass Batch ◽  
Foam Glass ◽  
Foaming Agent ◽  
Additive Type ◽  
Highly Porous ◽  
Material Porosity

The article discusses the peculiarities of the "water-glass – glycerol" foaming mixture components interaction during foam glass synthesis. The important role of the foaming additive type in the foam glass porous structure formation was described, the main foaming substances were listed. The obtaining and researching technology of the samples was described, the compositions of the initial batches using the "water-glass – glycerol" mixture were developed. It was shown that a material with a highly porous structure and density below 500 kg/m3 can be obtained only with the combined introduction of water-glass and glycerol. In this case, mixtures with a predominance of water-glass in the foaming mixture possess optimal properties. Using DSC, it was shown that the addition of water-glass to the mixture completely eliminates the evaporation of glycerol at lower temperatures and intensifies its combustion at higher temperatures. Thus, the addition of water-glass to the glycerol-based foam glass batch allows glycerol to be saved up to higher temperatures that increases the resulting material porosity.

Action of a phorbol ester on B-cells: potentiation of stimulant-induced electrical activity

1985 ◽  
Vol 248 (5) ◽  
pp. C527-C534 ◽  
Author(s):  
C. S. Pace ◽  
K. T. Goldsmith
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Electrical Activity ◽  
Electrical Response ◽  
Tumor Promoter ◽  
Kinase C ◽  
Cell Plasma ◽  
Lag Period

The possible role of protein kinase c in regulating the electrical events in the B-cell plasma membrane was examined by using the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), a known activator of this enzyme. TPA has been found to enhance glucose- and sulfonylurea-induced insulin secretion with little or no effect on the fluxes of 86Rb+ or 45Ca2+ across the plasma membrane. TPA, 0.2 microM, did not influence the membrane potential from 0 to 5.6 mM glucose but increased by two- to threefold the fraction of the plateau phase of the oscillatory electrical activity induced by 7.0-11.1 mM glucose. This effect of TPA was completely blocked by 0.5 mM spermidine, an inhibitor of protein kinase c. However, spermidine had no influence on the electrical activity elicited by glucose alone. Glyburide, 10 nM, initiated slow depolarization and constant spike activity after about 18 and 25 min, respectively. TPA or 2.8 mM glucose reduced the lag period for glyburide to elicit an electrical response by about 75%. The duration of the spikes was increased two- to threefold by the presence of glucose or TPA with glyburide. There were also characteristic differences in the shape of the spikes under each experimental condition. Spermidine inhibited the influence of glucose, but not TPA, on the glyburide-induced electrical response. These results indicate that TPA may influence stimulant-induced electrical events via protein kinase c or by directly altering the ionic permeability of the plasma membrane.

Role of the porous structure of the hemosorbent in the sorption of large molecules

1987 ◽  
Vol 21 (2) ◽  
pp. 149-152
Author(s):  
N. M. Kaznacheeva ◽  
S. I. Surinova ◽  
S. P. Valueva ◽  
B. S. �l'tsefon ◽  
G. S. Golovina
Keyword(s):  
Porous Structure ◽  
Large Molecules

Processes of the Foaming Mixture’ Components Interaction during the Foam Glass Synthesis

2020 ◽  
Vol 992 ◽  
pp. 271-276
Author(s):  
B.M. Goltsman ◽  
L.A. Yatsenko ◽  
Elena A. Yatsenko
Keyword(s):  
Porous Structure ◽  
Internal Structure ◽  
Foam Glass ◽  
Combustion Process ◽  
Structure And Properties ◽  
Stabilizing Agent

The prospects for the use of foam glass in construction were described. The modern compositions of foaming mixtures for foam glass synthesis were considered. Compositions for studying the influence of the foaming mixture components on the formation of foam glass porous structure were developed, their internal structure and properties were studied. The role of each component of the mixture on its foaming was revealed. Glycerol is a pore-forming agent, which decomposes and produces foaming gases. Waterglass is a stabilizing agent reducing glycerol combustion process. Recommendations on the application of the described patterns in the foam glass synthesis were given.

The role of porous structure copolymers as catalytic systems carriers

Polimery ◽  
2003 ◽  
Vol 48 (07/08) ◽  
pp. 490-498 ◽  
Author(s):  
BOZENA KOLARZ ◽  
IZABELA OWSIK
Keyword(s):  
Porous Structure ◽  
Catalytic Systems
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