Uppsala University

About: Uppsala University is a education organization based out in Uppsala, Sweden. It is known for research contribution in the topics: Population & Insulin. The organization has 36485 authors who have published 107509 publications receiving 4220668 citations. The organization is also known as: Uppsala universitet & uu.se.

Water at Interfaces

Abstract: The interfaces of neat water and aqueous solutions play a prominent role in many technological processes and in the environment. Examples of aqueous interfaces are ultrathin water films that cover most hydrophilic surfaces under ambient relative humidities, the liquid/solid interface which drives many electrochemical reactions, and the liquid/vapor interface, which governs the uptake and release of trace gases by the oceans and cloud droplets. In this article we review some of the recent experimental and theoretical advances in our knowledge of the properties of aqueous interfaces and discuss open questions and gaps in our understanding.

Flora of Ethiopia and Eritrea

Abstract: After several years of planning and fund-hunting the Flora of Ethiopia project was launched in 1980, funded by SAREC (Swedish Agency for Research Cooperation with Developing Countries) with the aim of producing a Flora of Ethiopia, training of Ethiopian students to Ph.D. in Systematic Botany, and strengthening the National Herbarium in Addis Ababa and its library. Four Ethiopian botanists have now received their Ph.D. in Uppsala and a considerable number of collections has been added in the National Herbarium. Vol. 3 of the Flora was published in 1989 and thanks to the combined efforts of many botanists accounts for most of the remaining families for Flora of Ethiopia are now available in a more or less finalized version.

Chemical Fixation of Enzymes to Cyanogen Halide Activated Polysaccharide Carriers

Abstract: Water-insolubel chymotrypsin, trypsin and papain have been synthesized by covalent fixation of the enzymes to beads of cross-linked dextran (Sephadex®), beads of agarose, and cellulose powder. The fixation procedure involves two simple steps: (a) activation of the polysaccharide polymer by a cyanogen halide; (b) coupling of the protein to the activated polymer in slighly alkaline medium. The activation process can be controlled so as to retain certain useful or essential properties of the carrier material, such as particle shape and swelling capacity. The enzyme conjugates of Sephadex and agarose are therefore especialy suitable for use in the column format. The coupling process is so mild that a large portion of the inherent enzymic activity is conserved. However, the steric properties and other features of the carrier framework often prevents full manifestatuion of the fixed activity. Catalysts that are highly efficient toward small substrates are easily obtainable. Teh agarose-bound enzymes can even exhibit high activities toward large proteins. Conjugates of the latter type should therefore be particularly useful for the digestion of prtoeins.

Structure and bonding of water on Pt(111).

Abstract: We address the adsorption of water on Pt(111) using x-ray absorption, x-ray emission, and x-ray photoelectron spectroscopy along with calculations in the framework of density functional theory. Using the direct relationship between the electronic structure and adsorbate geometry, we show that in the first layer all the molecules bind directly to the surface and to each other through the in-layer H bonds without dissociation, creating a nearly flat overlayer. The water molecules are adsorbed through alternating metal-oxygen (M-O) and metal-hydrogen (M-HO) bonds.