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Hydrogen-bond catalysis is a type of organocatalysis that relies on use of hydrogen bonding interactions to accelerate and control organic reactions. In biological systems, hydrogen bonding plays a key role in many enzymatic reactions, both in orienting the substrate molecules and lowering barriers to reaction. [ 1 ]
Schreiner's thiourea, N,N'-bis3,5-bis(trifluormethyl)phenyl thiourea, combines all structural features for double H-bonding mediated organocatalysis: electron-poor; rigid structure; non-coordinating, electron withdrawing substituents in 3,4, and/or 5 position of a phenyl ring; the 3,5-bis(trifluoromethyl)phenyl-group is the preferred substituent
In organic chemistry, organocatalysis is a form of catalysis in which the rate of a chemical reaction is increased by an organic catalyst. This "organocatalyst" consists of carbon , hydrogen , sulfur and other nonmetal elements found in organic compounds.
Arteries have a superior long-term patency (expandedness), but veins are more commonly used due to their practicality. [40] Arterial grafts originate from the part of the internal thoracic artery (ITA) that runs near the edge of sternum, and can easily be mobilized and anastomosed to the native target vessel of the heart. The left artery is ...
Proline organocatalysis is the use of proline as an organocatalyst in organic chemistry. This theme is often considered the starting point for the area of organocatalysis, even though early discoveries went unappreciated. [1] Modifications, such as MacMillan’s catalyst and Jorgensen's catalysts, proceed with excellent stereocontrol. [2]: 5574 [3]
It is used for the treatment or palliative care of chronic kidney failure in small animals. The solution can be administered intravenously or subcutaneously . Administering the fluids subcutaneously allows the solution to be readily given to the animal by a trained layperson, as it is not required that a vein be located.
Segmental arterial mediolysis (SAM) is a rare disorder of the arteries characterized by the development of aneurysms, blood clots, narrowing of the arteries (stenoses), and blood collections (hematomas) in the affected distribution. [1] [2] SAM most commonly affects the arteries supplying the intestines and abdominal organs. [citation needed]
Aqueous biphasic systems (ABS) or aqueous two-phase systems (ATPS) are clean alternatives for traditional organic-water solvent extraction systems.. ABS are formed when either two polymers, one polymer and one kosmotropic salt, or two salts (one chaotropic salt and the other a kosmotropic salt) are mixed at appropriate concentrations or at a particular temperature.