Response ofBacillus subtilis spores to dehydration and UV irradiation at extremely low temperatures

1996 ◽  
Vol 26 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Klaus Dose ◽  
Anke Klein
Keyword(s):  
Uv Irradiation ◽  
Low Temperatures ◽  
Ofbacillus Subtilis

Cluster–Micelle Transition of a Thermo- and Photoresponsive ABC Triblock Copolymer in an Ionic Liquid

2019 ◽  
Vol 72 (2) ◽  
pp. 155
Author(s):  
Aya Saruwatari ◽  
Kei Hashimoto ◽  
Ryota Tamate ◽  
Ryoji Usui ◽  
Hisashi Kokubo ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Transition Temperature ◽  
Ethylene Oxide ◽  
Uv Irradiation ◽  
Low Temperatures ◽  
Triblock Copolymer ◽  
Abc Triblock Copolymer ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene ◽  
Azobenzene Groups

We report the photocontrollable micelle–cluster transition of an ABC-type triblock copolymer in an ionic liquid (IL). Polystyrene-b-poly(ethylene oxide)-b-poly(4-phenylazobenzyl acrylamide-r-N-isopropylacrylamide) (PSt-b-PEO-b-P(AzoBnAm-r-NIPAm)) was synthesised, where PSt is IL-phobic, PEO is IL-philic, and P(AzoBnAm-r-NIPAm) is photo- and thermoresponsive in the IL. At high temperatures, the triblock copolymer forms micelles with PSt cores; furthermore, at low temperatures, micelles self-assemble into clusters induced by the aggregation of P(AzoBnAm-r-NIPAm). Under UV irradiation, the micelles form clusters at lower temperatures than that in the dark because of the change in the solubility of P(AzoBnAm-r-NIPAm) induced by photoisomerisation of the azobenzene groups, indicating that this triblock copolymer has a photocontrollable micelle–cluster transition temperature.

scholarly journals UV irradiation/cold shock-mediated apoptosis is switched to bubbling cell death at low temperatures

Oncotarget ◽  
2015 ◽  
Vol 6 (10) ◽  
pp. 8007-8018 ◽  
Author(s):  
Szu-Jung Chen ◽  
Pei-Wen Lin ◽  
Hsin-Ping Lin ◽  
Shenq-Shyang Huang ◽  
Feng-Jie Lai ◽  
...  
Keyword(s):  
Cell Death ◽  
Uv Irradiation ◽  
Low Temperatures ◽  
Cold Shock

[2 + 2] Photochemical modulation of the Dy(iii) single-molecule magnet: opposite influence on the energy barrier and relaxation time

2017 ◽  
Vol 4 (8) ◽  
pp. 1311-1318 ◽  
Author(s):  
Long-Fei Wang ◽  
Jiang-Zhen Qiu ◽  
Yan-Cong Chen ◽  
Jun-Liang Liu ◽  
Quan-Wen Li ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Uv Irradiation ◽  
Single Molecule ◽  
Low Temperatures ◽  
Energy Barrier ◽  
Magnetic Relaxation ◽  
Single Molecule Magnet ◽  
Raman Process

The photochemical [2 + 2] reaction on a mononuclear Dy(iii) single-molecule magnet leads to the higher energy barrier after UV irradiation, along with the shorter magnetic relaxation time that is due to the acceleration of Raman process at low temperatures.

Bonding of polymer microstructures by UV irradiation and subsequent welding at low temperatures

2004 ◽  
Vol 10 (5) ◽  
pp. 372-374 ◽  
Author(s):  
R. Truckenmüller ◽  
P. Henzi ◽  
D. Herrmann ◽  
V. Saile ◽  
W.K. Schomburg
Keyword(s):  
Uv Irradiation ◽  
Low Temperatures ◽  
Polymer Microstructures

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.

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