@misc{MoralesLeinenCampoetal., author = {Morales, Carlos and Leinen, Dietmar and Campo, Adolfo del and Ares, Jos{\´e} Ram{\´o}n and S{\´a}nchez, Carlos and Flege, Jan Ingo and Guti{\´e}rrez, Alejandro and Prieto, Pilar and Soriano, Leonardo}, title = {Growth and characterization of ZnO thin films at low temperatures: from room temperature to -120 °C}, series = {Journal of Alloys and Compounds}, volume = {884}, journal = {Journal of Alloys and Compounds}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2021.161056}, abstract = {ZnO thin films have been grown by e-beam evaporation in the range from room temperature to - 120 °C on two types of substrates, Al2O3 (0001) and Si (100). Although the ZnO/Al2O3 system has been thoroughly characterized, including optical and electrical techniques, the morphological, structural and chemical properties show no significant differences between both substrates. Thus, the general features of the ZnO growth mode at low temperature can be generalized. The relatively low growth temperatures reduce the diffusion of atoms at the surface, which leads to morphological and chemical changes. As the temperature decreases, the growth mode changes from a van der Drift model to a gradual bilayer system composed of an interfacial layer in contact with the substrate and a second columnar-based layer. This second well-ordered film disappears for the lowest temperatures while a Zn-rich interface in contact with the substrate emerges. Precisely from this interface, Zn-rich whiskers develop under the ZnO film and cause the loss of adhesion at temperatures below - 100 °C. These extreme temperatures also affect the crystal size, lattice strain, and total amount of oxygen vacancies. The behavior of the optical and electrical properties in terms of band gap, transparency, electrical resistivity, and Seebeck coefficient is discussed in the light of structural and chemical characterization. Samples grown at 0 °C exhibit an enhanced transmittance compared to those grown at room temperature while preserving similar electrical resistivity values and natural n-type doping. These results open a promising route to enhance ZnO films properties below the typical high temperature window.}, language = {en} } @misc{GomezdeSantosGonzalezBenjumeaFernandezGarciaetal., author = {Gomez de Santos, Patricia and Gonz{\´a}lez-Benjumea, Alejandro and Fernandez-Garcia, Angela and Aranda, Carmen and Wu, Yinqi and But, Andrada and Molina-Espeja, Patricia and Mat{\´e}, Diana M. and Gonzalez-Perez, David and Zhang, Wuyuan and Kiebist, Jan and Scheibner, Katrin and Hofrichter, Martin and Swiderek, Katarzyna and Moliner, Vicent and Sanz-Aparicio, Julia and Hollmann, Frank and Guti{\´e}rrez, Ana and Alcalde, Miguel}, title = {Engineering a highly regioselective fungal peroxygenase for the synthesis of hydroxy fatty acids}, series = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker}, volume = {62}, journal = {Angewandte Chemie : a journal of the Gesellschaft Deutscher Chemiker}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1521-3773}, doi = {10.1002/anie.202217372}, pages = {1 -- 9}, abstract = {The hydroxylation of fatty acids is an appealing reaction in synthetic chemistry, although the lack of selective catalysts hampers its industrial implementation. In this study, we have engineered a highly regioselective fungal peroxygenase for the ω-1 hydroxylation of fatty acids with quenched stepwise over-oxidation. One single mutation near the Phe catalytic tripod narrowed the heme cavity, promoting a dramatic shift toward subterminal hydroxylation with a drop in the over-oxidation activity. While crystallographic soaking experiments and molecular dynamic simulations shed light on this unique oxidation pattern, the selective biocatalyst was produced by Pichia pastoris at 0.4 g L-1 in a fed-batch bioreactor and used in the preparative synthesis of 1.4 g of (ω-1) hydroxytetradecanoic acid with 95 \% regioselectivity and 83 \% ee for the S enantiomer.}, language = {en} }