Complexation of some univalent organic cations with hexaethyl p-tert-butylcalix[6]arene hexaacetate in nitrobenzene saturated water

Porous crosslinked copolymers of methacrylic acid with N-(2-hydroxypropyl) methacrylamide (HPMA) or (2-hydroxyethyl) methacrylate were prepared, and the relationship between their structure and the sorption of papain, bovine serumalbumin, chymotrypsinogen, pepsin, ovalbumin, insulin, novocain and oleandomycin were investigated. The presence of hydrophilic components in the gel structure makes possible additional interactions between sorbent and the compound sorbed. The occurrence of additional interactions (probably hydrogen bonds) is more pronounced with cation exchangers containing the (2-hydroxyethyl) methacrylate monomeric unit, which favourably affects the sorption of univalent organic cations but at the same time contributes to the denaturation of sorbed proteins. In contrast to univalent organic cations, cation exchangers containing the N-(2-hydroxypropyl) methacrylamide monomeric unit are more advantageous in the sorption of proteins, because due to the lower extent of additional interactions no irreversible denaturation of sorbed labile proteins takes place in this case.

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Complexation of some univalent organic cations with benzo-18-crown-6 in nitrobenzene saturated with water

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-012-1836-5 ◽

2012 ◽

Vol 295 (1) ◽

pp. 767-770

Author(s):

E. Makrlík ◽

P. Selucký ◽

P. Vaňura

Keyword(s):

Organic Cations ◽

Univalent Organic Cations

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Replication of Wet Objects and Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050524 ◽

1974 ◽

Vol 32 ◽

pp. 102-103

Author(s):

S. Basu ◽

D. F. Parsons

Keyword(s):

Water Vapor Pressure ◽

High Vacuum ◽

Polystyrene Latex ◽

Vacuum System ◽

Saturated Water Vapor ◽

Replication Method ◽

New Methods ◽

Saturated Water ◽

Water Vapors ◽

Intermediate Chamber

We are approaching the invasiveness of cancer cells from the studies of their wet surface morphology which should distinguish them from their normal counterparts. In this report attempts have been made to provide physical basis and background work to a wet replication method with a differentially pumped hydration chamber (Fig. 1) (1,2), to apply this knowledge for obtaining replica of some specimens of known features (e.g. polystyrene latex) and finally to realize more specific problems and to improvize new methods and instrumentation for their rectification. In principle, the evaporant molecules penetrate through a pair of apertures (250, 350μ), through water vapors and is, then, deposited on the specimen. An intermediate chamber between the apertures is pumped independently of the high vacuum system. The size of the apertures is sufficiently small so that full saturated water vapor pressure is maintained near the specimen.

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Membrane-bound vesicles associated with the microvilli in the midgut of the freshwater microcrustacean, Daphnia magna

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100076135 ◽

1983 ◽

Vol 41 ◽

pp. 480-481

Author(s):

Patricia L. Jansma

Keyword(s):

Daphnia Magna ◽

Intestinal Epithelial Cells ◽

Uranyl Acetate ◽

Intestinal Epithelial ◽

Chlamydomonas Reinhardii ◽

Thin Sections ◽

Saturated Water ◽

Cacodylate Buffer ◽

Membrane Bound ◽

Ethanol Series

The presence of the membrane bound vesicles or blebs on the intestinal epithelial cells has been demonstrated in a variety of vertebrates such as chicks, piglets, hamsters, and humans. The only invertebrates shown to have these microvillar blebs are two species of f1ies. While investigating the digestive processes of the freshwater microcrustacean, Daphnia magna, the presence of these microvillar blebs was noticed.Daphnia magna fed in a suspension of axenically grown green alga, Chlamydomonas reinhardii for one hour were narcotized with CO2 saturated water. The intestinal tracts were excised in 2% glutaraldehyde in 0.2 M cacodyl ate buffer and then placed in fresh 2% glutaraldehyde for one hour. After rinsing in 0.1 M cacodylate buffer, the sample was postfixed in 2% OsO4, dehydrated with a graded ethanol series, infiltrated and embedded with Epon-Araldite. Thin sections were stained with uranyl acetate and Reynolds lead citrate before viewing with the Philips EM 200.

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ESEM - A multipurpose surface Electron Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100144607 ◽

1986 ◽

Vol 44 ◽

pp. 632-633 ◽

Cited By ~ 2

Author(s):

G.D. Danilatos

Keyword(s):

Electron Microscope ◽

Room Temperature ◽

Environmental Scanning ◽

Gas Composition ◽

Saturated Water Vapor ◽

Surface Electron ◽

Current State ◽

Saturated Water ◽

New Type ◽

Temperature And Pressure

Over recent years a new type of electron microscope - the environmental scanning electron microscope (ESEM) - has been developed for the examination of specimen surfaces in the presence of gases. A detailed series of reports on the system has appeared elsewhere. A review summary of the current state and potential of the system is presented here.The gas composition, temperature and pressure can be varied in the specimen chamber of the ESEM. With air, the pressure can be up to one atmosphere (about 1000 mbar). Environments with fully saturated water vapor only at room temperature (20-30 mbar) can be easily maintained whilst liquid water or other solutions, together with uncoated specimens, can be imaged routinely during various applications.

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In-Situ Observation of Clay Minerals Hydrated and Intercalated With Liquid Chemicals Using Film-Sealed Environmental Cell

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000908 ◽

1980 ◽

Vol 38 ◽

pp. 208-209 ◽

Cited By ~ 1

Author(s):

K. Fukushima ◽

N. Kohyama ◽

A. Fukami

Keyword(s):

Carbon Film ◽

Resolving Power ◽

In Situ Observation ◽

Interlayer Water ◽

Saturated Water ◽

Structure Changes ◽

Environmental Cell ◽

Gas Layer ◽

20 Nm

A film-sealed high resolution environmental cell(E.C) for observing hydrated materials had been developed by us(l). Main specification of the E.C. is as follows: 1) Accelerated voltage; 100 kV. 2) Gas in the E.C.; saturated water vapour with carrier gas of 50 Torr. 3) Thickness of gas layer; 50 μm. 4) Sealing film; evaporated carbon film(20 nm thick) with plastic microgrid. 5) Resolving power; 1 nm. 6) Transmittance of electron beam; 60% at 100 kV. The E.C. had been successfully applied to the study of hydrated halloysite(2) (3). Kaolin minerals have no interlayer water and are basically non-expandable but form intercalation compounds with some specific chemicals such as hydrazine, formamide and etc. Because of these compounds being mostly changed in vacuum, we tried to reveal the structure changes between in wet air and in vacuum of kaolin minerals intercalated with hydrazine and of hydrated state of montmori1lonite using the E.C. developed by us.

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