Visible-light-mediated cleavage of polymer chains under physiological conditions via quinone photoreduction and trimethyl lock

2017 ◽  
Vol 53 (89) ◽  
pp. 12076-12079 ◽  
Author(s):  
Vinh X. Truong ◽  
Fanyi Li ◽  
Francesca Ercole ◽  
John S. Forsythe

We introduce a click and visible-light triggered unclick approach via thio-bromo reaction and hydroquinone photoreduction/trimethyl lock cleavage for polymer modifications.

2020 ◽  
Vol 41 (1) ◽  
pp. 2070001
Author(s):  
Hendrik Frisch ◽  
Daniel Kodura ◽  
Fabian R. Bloesser ◽  
Lukas Michalek ◽  
Christopher Barner‐Kowollik
Keyword(s):  

2019 ◽  
Vol 41 (1) ◽  
pp. 1900414 ◽  
Author(s):  
Hendrik Frisch ◽  
Daniel Kodura ◽  
Fabian R. Bloesser ◽  
Lukas Michalek ◽  
Christopher Barner‐Kowollik
Keyword(s):  

2018 ◽  
Vol 54 (28) ◽  
pp. 3476-3479 ◽  
Author(s):  
Carolin Heiler ◽  
Simon Bastian ◽  
Paul Lederhose ◽  
James P. Blinco ◽  
Eva Blasco ◽  
...  

A simple and versatile tool for generating fluorescent single chain polymer nanoparticles with visible light.


2019 ◽  
Vol 10 (33) ◽  
pp. 4513-4518 ◽  
Author(s):  
Janin T. Offenloch ◽  
Eva Blasco ◽  
Simon Bastian ◽  
Christopher Barner-Kowollik ◽  
Hatice Mutlu

We introduce a facile photoinduced self-reporting crosslinking methodology for the compaction of polymer chains in highly diluted solution.


Author(s):  
Å. Thureson-Klein

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.


Author(s):  
Shawn Williams ◽  
Xiaodong Zhang ◽  
Susan Lamm ◽  
Jack Van’t Hof

The Scanning Transmission X-ray Microscope (STXM) is well suited for investigating metaphase chromosome structure. The absorption cross-section of soft x-rays having energies between the carbon and oxygen K edges (284 - 531 eV) is 6 - 9.5 times greater for organic specimens than for water, which permits one to examine unstained, wet biological specimens with resolution superior to that attainable using visible light. The attenuation length of the x-rays is suitable for imaging micron thick specimens without sectioning. This large difference in cross-section yields good specimen contrast, so that fewer soft x-rays than electrons are required to image wet biological specimens at a given resolution. But most imaging techniques delivering better resolution than visible light produce radiation damage. Soft x-rays are known to be very effective in damaging biological specimens. The STXM is constructed to minimize specimen dose, but it is important to measure the actual damage induced as a function of dose in order to determine the dose range within which radiation damage does not compromise image quality.


Author(s):  
C. Jacobsen ◽  
J. Fu ◽  
S. Mayer ◽  
Y. Wang ◽  
S. Williams

In scanning luminescence x-ray microscopy (SLXM), a high resolution x-ray probe is used to excite visible light emission (see Figs. 1 and 2). The technique has been developed with a goal of localizing dye-tagged biochemically active sites and structures at 50 nm resolution in thick, hydrated biological specimens. Following our initial efforts, Moronne et al. have begun to develop probes based on biotinylated terbium; we report here our progress towards using microspheres for tagging.Our initial experiments with microspheres were based on commercially-available carboxyl latex spheres which emitted ~ 5 visible light photons per x-ray absorbed, and which showed good resistance to bleaching under x-ray irradiation. Other work (such as that by Guo et al.) has shown that such spheres can be used for a variety of specific labelling applications. Our first efforts have been aimed at labelling ƒ actin in Chinese hamster ovarian (CHO) cells. By using a detergent/fixative protocol to load spheres into cells with permeabilized membranes and preserved morphology, we have succeeded in using commercial dye-loaded, spreptavidin-coated 0.03μm polystyrene spheres linked to biotin phalloidon to label f actin (see Fig. 3).


Author(s):  
N. Seki ◽  
Y. Toyama ◽  
T. Nagano

It is believed that i ntramembra.nous sterols play an essential role in membrane stability and permeability. To investigate the distribution changes of sterols in sperm membrane during epididymal maturation and capacitation, filipin has been used as a cytochemical probe for the detection for membrane sterols. Using this technique in combination with freeze fracturing, we examined the boar spermatozoa under various physiological conditions.The spermatozoa were collected from: 1) caput, corpus and cauda epididymides, 2) sperm rich fraction of ejaculates, and 3)the uterus 2hr after natural coition. They were fixed with 2.5% glutaraldehyde in 0.05M cacodylate buffer (pH 7.4), and treated with the filipin solution (final concentration : 0.02.0.05%) for 24hr at 4°C with constant agitation. After the filipin treatment, replicas were made by conventional freeze-fracture technique. The density of filipin-sterol complexes (FSCs) was determined in the E face of the plasma membrane of head regions.


2019 ◽  
Vol 6 (21) ◽  
pp. 3693-3697 ◽  
Author(s):  
Jiu-Jian Ji ◽  
Zhi-Qiang Zhu ◽  
Li-Jin Xiao ◽  
Dong Guo ◽  
Xiao Zhu ◽  
...  
Keyword(s):  

A novel, green and efficient visible-light-promoted decarboxylative aminoalkylation reaction of imidazo[1,2-a]pyridines with N-aryl glycines has been described.


Sign in / Sign up

Export Citation Format

Share Document