In the Arctic and Antarctic seas the water gets cold to minus 1.9 C in winter, but somehow some fish live there. These cold-blooded creatures survive in the icy water because the blood in their veins contains antifreeze proteins and glycoproteins. High levels of the antifreeze proteins are found in the blood serum, they are present in cell cytoplasm and all body fluids except urine. Due to their structure, molecules of antifreeze glycoproteins (AFGP) prevent growth of ice crystals. Natural antifreezes draw researchers` attention as prospective stabilizers for cryobiology. Scientists from the Institute of Cell Biophysics of Russian Academy of Sciences and from the Institute of Fishery have shown that AFGP help to preserve sperm cells at low temperature.
Biologists have often need to save sperm, tissue samples or cell cultures. The preparations are kept in liquid nitrogen at a temperature of -196 degrees C. To prevent their death, the cells are put into a special cryopreserving medium, which is rather toxic. Russian scientists added AFGP to the media and it became possible to half the amount of toxic compounds. The frozen in such way sperm retained its vitality after thawing and at the right amount of antifreeze the spermatozoid activity even increases.
Liquid nitrogen suits well for long-term storage, but in some cases it is not convenient. After few days nitrogen evaporates and needs replenishment. You also have to warm up the preparations in a special way so that came to life. Not all cells stand very low temperatures, for example, donor organs are not put into liquid nitrogen and they do not have to be kept for several months. If a material should be preserved for several days, it is put into the refrigerator, where the temperature is 4 C. Still, many cells die even in these conditions. The scientists have found that AGFP help in these cases too. They have experimented with sperm of middle-Russian carp. The antifreeze was extracted from the blood serum of cod Gadus morrhua, which lives in the Barents Sea. Usually only 60% of sperm survive after one hour storage in the fridge and 5% after 5 day storage. Adding antifreezes resulted in 2.5 to 6 times increase in the cell activity (the result depended upon the time of storage and the solution composition). AGFP are active in concentration of 2-10 mg/ml.
Natalia Reznik | alphagalileo
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Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
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For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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