Relocation of Internal Bound Water in Bacteriorhodopsin during the Photoreaction of M at Low Temperatures:  An FTIR Study†

Biochemistry ◽  
2000 ◽  
Vol 39 (33) ◽  
pp. 10154-10162 ◽  
Author(s):  
Akio Maeda ◽  
Farol L. Tomson ◽  
Robert B. Gennis ◽  
Hideki Kandori ◽  
Thomas G. Ebrey ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Bound Water ◽  
Ftir Study

Low-temperature FTIR spectroscopy provides evidence for protein-bound water molecules in eubacterial light-driven ion pumps

2018 ◽  
Vol 20 (5) ◽  
pp. 3165-3171 ◽  
Author(s):  
Yurika Nomura ◽  
Shota Ito ◽  
Miwako Teranishi ◽  
Hikaru Ono ◽  
Keiichi Inoue ◽  
...  
Keyword(s):  
Low Temperature ◽  
Water Molecule ◽  
Ftir Spectroscopy ◽  
Proton Pump ◽  
Bound Water ◽  
Water Molecules ◽  
Ion Pumps ◽  
Functional Determinant ◽  
Ftir Study ◽  
Hydrogen Bonded

The present FTIR study showed that eubacterial light-driven H+, Na+ and Cl− pump rhodopsins contain strongly hydrogen-bonded water molecule, the functional determinant of light-driven proton pump. This explains well the asymmetric functional conversions of light-driven ion pumps.

FTIR study of ammonia formation via the successive hydrogenation of N atoms trapped in a solid N2 matrix at low temperatures

2011 ◽  
Vol 13 (35) ◽  
pp. 15798 ◽  
Author(s):  
Hiroshi Hidaka ◽  
Motohiro Watanabe ◽  
Akira Kouchi ◽  
Naoki Watanabe
Keyword(s):  
Low Temperatures ◽  
Ftir Study ◽  
Ammonia Formation ◽  
Solid N2

AN X-RAY METHOD FOR THE STUDY OF "BOUND WATER" IN HYDROPHILIC COLLOIDS AT LOW TEMPERATURES

1935 ◽  
Vol 13b (4) ◽  
pp. 218-227 ◽  
Author(s):  
W. H. Barnes ◽  
W. F. Hampton
Keyword(s):  
Qualitative Study ◽  
Low Temperatures ◽  
Bound Water ◽  
New Method ◽  
Ray Method ◽  
X Ray ◽  
Temperature Range ◽  
Methods Of Analysis ◽  
Gelatin Gels ◽  
Ray Methods

A new method for the study of hydrophilic colloids by the application of X-ray methods of analysis to the frozen gels is described. The possibilities of the method and its limitations are shown by a qualitative study of the amount, and variation with temperature, of the so-called "bound" water in gelatin gels over the temperature range − 3° to − 50 °C.

FROST-HARDENING STUDIES WITH LIVING CELLS: I. OSMOTIC AND BOUND WATER CHANGES IN RELATION TO FROST RESISTANCE AND THE SEASONAL CYCLE

1936 ◽  
Vol 14c (7) ◽  
pp. 267-284 ◽  
Author(s):  
J. Levitt ◽  
G. W. Scarth
Keyword(s):  
Osmotic Pressure ◽  
Cell Volume ◽  
Low Temperatures ◽  
Frost Resistance ◽  
Woody Plants ◽  
Seasonal Cycle ◽  
Bound Water ◽  
Living Cells ◽  
Ice Formation ◽  
Frost Hardening

The osmotic pressure and non-solvent space of the cells of various types of plant were estimated by the plasmolytic method and related to frost resistance and the seasonal cycle.Osmotic pressure always rises with hardening and falls with dehardening, and it generally reaches higher values or begins to rise earlier in the hardier species and varieties.The effect of osmotic pressure in reducing the amount of ice formation is enhanced in woody plants by the condition that only about half the cell volume is occupied by the osmotically active solution. The remainder, i.e., the non-solvent space, is shown to consist partly of bound water and must therefore represent hydrophilic colloid. This occupies an even larger proportion of the sap vacuole than of the protoplasm, and it increases notably with hardening. This change, besides reducing intercellular ice, is regarded as protecting the most vulnerable part of the cell, viz., the vacuole, from being frozen at very low temperatures.

Interpretation of irradiation-induced changes in electron diffractograms and images of extinction contours at low temperatures

1984 ◽  
Vol 42 ◽  
pp. 268-269
Author(s):  
E. Knapek ◽  
H. Formanek ◽  
G. Lefranc ◽  
I. Dietrich
Keyword(s):  
Low Temperatures ◽  
Carbon Films ◽  
Organic Crystals ◽  
Wide Spread ◽  
Lens System ◽  
Preparation Conditions ◽  
Thin Carbon ◽  
Electron Diffractograms ◽  
Diffraction Patterns ◽  
Induced Changes

A few years ago results on cryoprotection of L-valine were reported, where the values of the critical fluence De i.e, the electron exposure which decreases the intensity of the diffraction reflections by a factor e, amounted to the order of 2000 + 1000 e/nm2. In the meantime a discrepancy arose, since several groups published De values between 100 e/nm2 and 1200 e/nm2 /1 - 4/. This disagreement and particularly the wide spread of the results induced us to investigate more thoroughly the behaviour of organic crystals at very low temperatures during electron irradiation.For this purpose large L-valine crystals with homogenuous thickness were deposited on holey carbon films, thin carbon films or Au-coated holey carbon films. These specimens were cooled down to nearly liquid helium temperature in an electron microscope with a superconducting lens system and irradiated with 200 keU-electrons. The progress of radiation damage under different preparation conditions has been observed with series of electron diffraction patterns and direct images of extinction contours.

Radiation Damage of Support Films

1981 ◽  
Vol 39 ◽  
pp. 28-29
Author(s):  
H.A. Cohen ◽  
W. Chiu
Keyword(s):  
Transfer Function ◽  
Low Temperatures ◽  
Carbon Support ◽  
Contrast Transfer Function ◽  
Electron Dose ◽  
Imaging Parameters ◽  
Negative Stain ◽  
Phase Corrections ◽  
Two Parameters ◽  
Medium Dose

The goal of imaging the finest detail possible in biological specimens leads to contradictory requirements for the choice of an electron dose. The dose should be as low as possible to minimize object damage, yet as high as possible to optimize image statistics. For specimens that are protected by low temperatures or for which the low resolution associated with negative stain is acceptable, the first condition may be partially relaxed, allowing the use of (for example) 6 to 10 e/Å2. However, this medium dose is marginal for obtaining the contrast transfer function (CTF) of the microscope, which is necessary to allow phase corrections to the image. We have explored two parameters that affect the CTF under medium dose conditions.Figure 1 displays the CTF for carbon (C, row 1) and triafol plus carbon (T+C, row 2). For any column, the images to which the CTF correspond were from a carbon covered hole (C) and the adjacent triafol plus carbon support film (T+C), both recorded on the same micrograph; therefore the imaging parameters of defocus, illumination angle, and electron statistics were identical.

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

Ultrastructure of the soil fungus, Geomyces pannorus

1984 ◽  
Vol 42 ◽  
pp. 738-739
Author(s):  
J. A. Traquair ◽  
E. G. Kokko
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Fine Structure ◽  
Low Temperatures ◽  
Soil Fungus ◽  
Organic Soils ◽  
Anatomical Studies ◽  
Transmission Electron ◽  
Electron Microscopical ◽  
Scanning Electron

With the advent of improved dehydration techniques, scanning electron microscopy has become routine in anatomical studies of fungi. Fine structure of hyphae and spore surfaces has been illustrated for many hyphomycetes, and yet, the ultrastructure of the ubiquitous soil fungus, Geomyces pannorus (Link) Sigler & Carmichael has been neglected. This presentation shows that scanning and transmission electron microscopical data must be correlated in resolving septal structure and conidial release in G. pannorus.Although it is reported to be cellulolytic but not keratinolytic, G. pannorus is found on human skin, animals, birds, mushrooms, dung, roots, and frozen meat in addition to various organic soils. In fact, it readily adapts to growth at low temperatures.

Structure and Orientation of As Precipitates in LT-MBE Grown GaAs

1991 ◽  
Vol 49 ◽  
pp. 900-901 ◽  
Author(s):  
Alain Claverie ◽  
Zuzanna Liliental-Weber
Keyword(s):  
Transport Properties ◽  
Layer Thickness ◽  
Growth Temperature ◽  
Low Temperatures ◽  
Lattice Parameter ◽  
Crystalline Quality ◽  
Insulating Properties ◽  
Lt Gaas

GaAs layers grown by MBE at low temperatures (in the 200°C range, LT-GaAs) have been reported to have very interesting electronic and transport properties. Previous studies have shown that, before annealing, the crystalline quality of the layers is related to the growth temperature. Lowering the temperature or increasing the layer thickness generally results in some columnar polycrystalline growth. For the best “temperature-thickness” combinations, the layers may be very As rich (up to 1.25%) resulting in an up to 0.15% increase of the lattice parameter, consistent with the excess As. Only after annealing are the technologically important semi-insulating properties of these layers observed. When annealed in As atmosphere at about 600°C a decrease of the lattice parameter to the substrate value is observed. TEM studies show formation of precipitates which are supposed to be As related since the average As concentration remains almost unchanged upon annealing.

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