Clauss process

H. Baehr, Gas Purification by the IG Alkacid Process and Sulfur Recovery by the IG Clauss Process , Refiner Natural Gas. Manuf, 17 [6] 237-44 (1938). 

Jackets, P., Clausse, N., Fernandez, M., Berti, A., Princen, F., Wewer, U., Sobel, M.E., and Castronovo, V. (1996a). Seventeen copies of the human 37 kDa laminin receptor precursor/ p40 ribosome-associated protein gene are processed pseudogenes arisen from retropositional events. Biochem. Biophys. Acta. 1305, 98-104. 

Now consider a more realistic situation, where the tumor vessels are 200 /urn apart and uniformly perfused, but Pi has increased in the center so that fluid extravasation, and hence convective transport of macromolecules across vessels, has stopped. In such a case the only way macromolecules extravasate in the center is by the slow process of diffusion across vessel walls. Also, they can reach the center from the periphery (where is near zero) by interstitial diffusion. As stated earlier, if the distance between the center and periphery is — 1 mm, it would take days for them to get there, and if it is 1 cm, it would take months (Clauss and Jain, 1990). If, owing to cellular proliferation, the central vessels have collapsed completely, then there is no delivery of macromolecules by blood flow to the necrotic center (Jain, 1988 Baxter and Jain, 1990). In such a case there are no molecules available for extravasation by diffusion across the vessel wall, and consequently the central concentration would be even lower (Baxter and Jain, 1990). However, once the molecules have arrived there, the central region may serve as a reservoir for slow release later when the periphery has been cleared by plasma. 

The reaction is a reversible stereospecific process which most likely proceeds via a concerted mechanism. An ab-initio study of the [2+2] cycloaddition reaction predicts that /3-lactam formation is a concerted suprafacial process . The stereospecificity of the [2+2] cycloaddition reaction is evidenced by the fact that cis- and trans- mieat-2 give the respective cycloadducts in high yields, indicating that the life of the ionic 1 1 adduct is shorter than the rotational time about the developing carbonium ion . The kinetics of the reaction were studied by Clauss , who found that CSI (chlorosulfonyl isocyanate) reacts... 

---