Rotation Barriers in Pyridinium Salts Depend on the Number of Available Ground State Conformations

The enthalpy and entropy of activation for the rotation about the C–N bond were measured in a series of five N-(1-hydroxybutan-2-yl)pyridinium salts, the 2,6-substituents being methyl, ethyl and isopropyl. Replacement of a methyl by an ethyl does not change the activation parameters, while replacement by an isopropyl increases both the activation enthalpy and the activation entropy. The latter is due to the decreased number of conformations available in the ground state. The activation entropies fit a simple model based on entropy of mixing

Building mutual trust: a framework project for implementing EU common standards in legal interpreting and translation

This edited volume addresses the establishment of core competencies for legal interpreters and translators(LITs) in the European common area, guides to core interpreter training curricula, the training of interpreter trainers, guidance for judicial professionals on working through legal interpreters and an extensive training materials resource bank

Comparative and Functional Genomics of Rhodococcus opacus PD630 for Biofuels Development

The Actinomycetales bacteria Rhodococcus opacus PD630 and Rhodococcus jostii RHA1 bioconvert a diverse range of organic substrates through lipid biosynthesis into large quantities of energy-rich triacylglycerols (TAGs). To describe the genetic basis of the Rhodococcus oleaginous metabolism, we sequenced and performed comparative analysis of the 9.27 Mb R. opacus PD630 genome. Metabolic-reconstruction assigned 2017 enzymatic reactions to the 8632 R. opacus PD630 genes we identified. Of these, 261 genes were implicated in the R. opacus PD630 TAGs cycle by metabolic reconstruction and gene family analysis. Rhodococcus synthesizes uncommon straight-chain odd-carbon fatty acids in high abundance and stores them as TAGs. We have identified these to be pentadecanoic, heptadecanoic, and cis-heptadecenoic acids. To identify bioconversion pathways, we screened R. opacus PD630, R. jostii RHA1, Ralstonia eutropha H16, and C. glutamicum 13032 for growth on 190 compounds. The results of the catabolic screen, phylogenetic analysis of the TAGs cycle enzymes, and metabolic product characterizations were integrated into a working model of prokaryotic oleaginy.Cambridge-MIT InstituteMassachusetts Institute of Technology. (Seed Grant program)Shell Oil CompanyNational Institute of Allergy and Infectious Diseases (U.S.)United States. National Institutes of HealthNational Institutes of Health. Department of Health and Human Services (Contract No. HHSN272200900006C

Probing gastrotrich taxonomy with DNA barcoding

Gastrotrichs represent a phylum of basal metazoans, living both in marine and freshwater environments, dimensionally comprised between 80 µm and 3 mm. Though taxonomic and biogeographic knowledge has been improved in the last years, little is known about the molecular aspects of this group. The aim of this study was to analyze these organisms by means of DNA barcoding which is a well-known technique consisting in the use of a gene sequence to affiliate an organism to a known species or to a new taxon. In this research, mitochondrial gene cytochrome oxidase I (COI) was used to identify gastrotrichs. It’s important to notice that no Gastrotrich COI sequence has been deposited in GenBank so far. Sampling of different populations of Turbanella cornuta and Paraturbanella teissieri, species considered to have a wide distribution, was carried out in Adriatic, Ligurian and Tyrrhenian Sea (Italy), Baltic Sea (Sweden), Atlantic Ocean (Canary Islands) and Arabian Gulf (Kuwait). DNA was extracted from some specimens, COI sequence amplified through PCR, and in the end the product was purified and sequenced. The obtained sequences were analyzed with NJ, MP and Bayesian Inference. It was possible to group in monophyletic clades, morphologically similar specimens belonging both to the same population and to diversely geographically distant populations. In particular, analyses revealed that specimens of T. cornuta from Adriatic, Ligurian, and Baltic Sea and Arabian Gulf can be considered distinct species, although similar. These results show that barcoding allows a more precise specific identification of Gastrotrichs; therefore this technique appears to be clearly useful when dealing with cryptic species, not easily distinguishable just by means of morphological characters. The wide application of this method will be of true interest also in reconsidering on new bases the paradoxical cosmopolitan distribution of several species

CCDC 2022503: Experimental Crystal Structure Determination

Related Article: Cory T. Kornman, Lei Li, Asmerom O. Weldeab, Ion Ghiviriga, Khalil A. Abboud, Ronald K. Castellano|2020|Chemical Science|11|10190|doi:10.1039/D0SC04409

Enlightening the Well-Controlled Photochemical Behavior of 1,1-Dicyanomethylene-3-Indanone-Functionalized π‑Conjugated Molecules

1,1-Dicyanomethylene-3-indanone (INCN) is a popular electron acceptor showcased in hundreds of push–pull oligomers, including some of the best nonfullerene acceptor (NFA) materials used in small molecule-based bulk-heterojunction (BHJ) organic photovoltaics (OPVs). Consequences of the configuration (i.e., Z or E) and conformation (i.e., s-cis or s-trans) of the exocyclic olefin that conjugates INCN to π-conjugated molecules have largely been ignored. Two recent reports have implicated Z/E photoisomerization in the photodegradation of popular NFAs like IT-4F when subjected to broad spectrum irradiation. Here, we elucidate through experiments and complementary ground- and excited-state computations the photochemical behavior of a family of eight INCN-functionalized donor–acceptor molecules varying in aryl and heteroaryl substitution, alkyl group substitution, and halogen functionalization on the INCN unit. Well-controlled Z/E photoisomerization using selective wavelengths of excitation spanning the ultraviolet and visible regions is observed in all cases yielding a range of Z/E photostationary state (PSS) distributions with no evidence of a previously reported photooxidation. Z/E photoisomerization followed by sequential pericyclic reactions, consistent with one recent literature report, is identified for just one target molecule upon irradiation at 454 nm. The alkyl group positioning on the thiophene ring neighboring the INCN is found to bias the conformational preferences of the target molecules and modulate access to this reaction pathway. All eight molecules undergo facile Z/E photoswitching over numerous cycles upon selective excitation. Overall, the work reveals the well-controlled photochemical behavior of INCN-functionalized π-systems and encourages their use in the design of future functional and organic materials and photoswitches

Influence of solvent on cyclic polynorbornene tacticity

Tacticity is critical to polymer properties