Graphene Oxide-Supported Oxime Palladacycles as Efficient Catalysts for the Suzuki–Miyaura Cross-Coupling Reaction of Aryl Bromides at Room Temperature under Aqueous Conditions

Palladacycles are highly efficient precatalysts in cross-coupling reactions whose immobilization on carbonaceous materials has been hardly studied. Herein, we report a detailed study on the synthesis and characterization of new oxime palladacycle-graphene oxide non-covalent materials along with their catalytic activity in the Suzuki–Miyaura reaction. Catalyst 1-GO, which has been fully characterized by ICP, XPS, TGA, and UV-Vis analyses has been demonstrated to be an efficient catalyst for the Suzuki–Miyaura coupling between aryl bromides and arylboronic acids using very low catalyst loadings (0.002 mol % of Pd) at room temperature under aqueous conditions.Financial support from the University of Alicante (UAUSTI16-03, UAUSTI16-10, VIGROB-173), the Spanish Ministerio de Economía, Industria y Competitividad (CTQ2015-66624-P) is acknowledged

Organocatalytic Asymmetric α-Chlorination of 1,3-Dicarbonyl Compounds Catalyzed by 2-Aminobenzimidazole Derivatives

Bifunctional chiral 2-aminobenzimidazole derivatives 1 and 2 catalyze the enantioselective stereodivergent α-chlorination of β-ketoesters and 1,3-diketone derivatives with up to 50% ee using N-chlorosuccinimide (NCS) or 2,3,4,4,5,6-hexachloro-2,5-cyclohexadien-1-one as electrophilic chlorine sources.Financial support from the University of Alicante (VIGROB-173, VIGROB-285, GRE12-03, UAUSTI13-01, UAUSTI13-02), and Spanish Ministerio de Economía y Competitividad (CTQ2011-24151) is acknowledged

Biological evolution and human cognition are analogous information processing systems

The mechanisms that govern biological evolution and human cognition are analogous, as both follow the same principles of natural information processing systems. In this article, we describe the following five principles that provide an analogy between biological evolution and human cognition: (a) Randomness as Genesis Principle and (b) Borrowing and Reorganizing Principle, which indicate how natural information processing systems obtain information; (c) Narrow Limits of Change Principle and (d) Information Store Principle, which indicate how information is processed and stored; and (e) Environmental Organizing and Linking Principle, which indicate how stored information is used to generate actions appropriate to an environment. In human cognition, these analogs only apply to cognitive processes associated with biologically secondary knowledge, the knowledge typically taught in educational institutions. Based on these five principles, cognitive load theory researchers have provided diverse prescriptions to optimize instructional activities and materials. We conclude by discussing general instructional implications and future research directions based on this analogy

A signal of competitive dominance in mid-latitude herbaceous plant communities

Understanding the main determinants of species coexistence across space and time is a central question in ecology. However, ecologists still know little about the scales and conditions at which biotic interactions matter and how these interact with the environment to structure species assemblages. Here we use recent theoretical developments to analyse plant distribution and trait data across Europe and find that plant height clustering is related to both evapotranspiration (ET) and gross primary productivity. This clustering is a signal of interspecies competition between plants, which is most evident in mid-latitude ecoregions, where conditions for growth (reflected in actual ET rates and gross primary productivities) are optimal. Away from this optimum, climate severity probably overrides the effect of competition, or other interactions become increasingly important. Our approach bridges the gap between species-rich competition theories and large-scale species distribution data analysisThis work was funded by the Spanish ‘Ministerio de Economía y Competitividad’ under the projects CGL2012-39964 and CGL2015-69043-P (D.A. and J.A.C.), by the Spanish ‘Ministerio de Ciencia, Innovación y Universidades’ under the project PGC2018-096577-B-I00 (D.A. and J.A.C.), and the Ramón y Cajal Fellowship program (RYC-2010-06545, D.A.). J.A.C. acknowledges partial financial support from the Department of Applied Mathematics (Universidad Politécnica de Madrid). S.C. acknowledges financial support from Banco Santander through grant no. PR87/19-2258

Visible light-promoted metal-free aerobic photooxidation of xanthenes, thioxanthenes and dihydroacridines in deep eutectic solvents

Benzylic systems such as 9H-xanthenes, 9H-thioxanthenes and 9,10-dihydroacridines can be easily oxidized to the corresponding xanthones, thioxanthones or acridones, respectively, in deep eutectic solvents by a visible blue light-promoted photooxidation procedure carried out using ambient air as oxidant in the presence of riboflavin tetraacetate as a metal-free photocatalyst. The obtained yields are high or almost quantitative, and the reaction media can be recovered and reused. The environmental friendliness of the protocol is demonstrated based on several green metrics.The authors acknowledge the financial support by the Spanish Ministerio de Ciencia e Innovación (PID2021-127332NB-I00), the Generalitat Valenciana (AICO 2021/013) and the University of Alicante (VIGROB-173 and UAUSTI 2022)

2-Aminobenzimidazole Organocatalyzed Asymmetric Amination of Cyclic 1,3-Dicarbonyl Compounds

The use of a trans-cyclohexanediamine benzimidazole derivative as a hydrogen-bond catalyst for the electrophilic amination of cyclic 1,3-dicarbonyl compounds is herein presented. High yields and enantioselectivities varying from moderate to excellent are generally obtained using mild reaction conditions and as low as 1 mol% of catalyst loading.Financial support from the University of Alicante (VIGROB-173, GRE12-03, UAUSTI13-01, UAUSTI13-02) is gratefully acknowledged

Diseño de un programa por computador para calcular los costos de la mecanización agrícola por cinco (5) métodos sicma

Empleando la metodología descrita por Towsend (1985), la cual considera cuatro (4) etapas: análisis, diseño, programación y validación, se elaboró un programa computarizado que permite calcular los costos por hora de la mecanización agrícola por los siguientes métodos: depreciación por línea recta (Valencia y González, 1973), método modificado de depreciación por línea recta (Reyes, 1985), depreciación por suma de dígitos (Álvarez, 1985), depreciación por suma de dígitos (Basto, 1985) y depreciación por el sistema de saldo decreciente (Bowers, 1977). Para estructurar el sistema, se definieron los datos de entrada, la información de salida tanto de carácter numérico como alfanumérico, así como las respectivas variables de acuerdo con la caracterización de cada uno de los métodos de cálculo de costos. Se establecieron los subsistemas o módulos respectivos, los cuales se determinaron para cada método y se definieron las relaciones posibles entre los subsistemas con el fin de compartir información. La fase de programación se llevó a cabo utilizando el lenguaje FOX PRO LAN, se crearon las respectivas bases de datos y se ejecutaron las diferentes rutinas con el fin de obtener los informes respectivos, los cuales se confrontaron con los resultados procesados manualmente. Los resultados del presente trabajo corresponden a las salidas impresas obtenidas para cada uno de los métodos de cálculo de costos.A computer program based on the methodology described by Towsend (1985) was designed. Such methodology considers four (4) steps: Analysis, design, programming, and validation. The program allows to estimate costs per hour in farm mechanization through the following methods: 1. Depreciation in straight line (Valencia y Gonzalez, 1973). 2. Modified method of depreciation in straight line (Reyes, 1985). 3. Depreciation by digits addition (Alvarez, 1985).  4.Depreciation by digits addition (Basto, 1985).  5.Depreciation by the balance-decreasing system (Bowers, 1977). Alfa numerical and numerical input and output data with its variables, according to characterization in each one of the cost calculating methods were defined in order to comform the information system. Subsystems were defined, based on each method, establishing the possible relationships between the various systems with the purpose of sharing information. The information system was fed to the computer when the programming was carried out. Then, database was established, to obtain the different reports for comparing them with those processed by hand, Thus, modifications and adjustments permiting the proper working of the program were carried out

Localized thinning for strain concentration in suspended germanium membranes and optical method for precise thickness measurement

We deposited Ge layers on (001) Si substrates by molecular beam epitaxy and used them to fabricate suspended membranes with high uniaxial tensile strain. We demonstrate a CMOS-compatible fabrication strategy to increase strain concentration and to eliminate the Ge buffer layer near the Ge/Si hetero-interface deposited at low temperature. This is achieved by a two-steps patterning and selective etching process. First, a bridge and neck shape is patterned in the Ge membrane, then the neck is thinned from both top and bottom sides. Uniaxial tensile strain values higher than 3% were measured by Raman scattering in a Ge membrane of 76 nm thickness. For the challenging thickness measurement on micrometer-size membranes suspended far away from the substrate a characterization method based on pump-and-probe reflectivity measurements was applied, using an asynchronous optical sampling technique.EC/FP7/628197/EU/Heat Propagation and Thermal Conductivity in Nanomaterials for Nanoscale Energy Management/HEATPRONAN

The evaluation of surface diffusion coefficients of gold and platinum atoms at electrochemical interfaces from combined STM-SEM imaging and electrochemical techniques

A simple method is presented for measuring the surface diffusion coefficients of Au and Pt atoms at electrodispersed electrodes of the same metals in contact with 0.5M H2SO4. The technique is based upon the time dependence of the surface roughness factor of electrodispersed metal overlayers. The method requires a model for the surface roughness of the metal structure. The model is deduced from microscopic measurements by a STM integrated into a conventional SEM microscope. This allows the relationship between the roughness factor and the area of the surface structure to be obtained. For Au and Pt in contact with an electrolyte solution, the values of our diffusion coefficients are higher than those reported in vacuum at the same temperature.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)Facultad de Ciencias Exacta