Examining Scientific Writing Styles from the Perspective of Linguistic Complexity

Publishing articles in high-impact English journals is difficult for scholars around the world, especially for non-native English-speaking scholars (NNESs), most of whom struggle with proficiency in English. In order to uncover the differences in English scientific writing between native English-speaking scholars (NESs) and NNESs, we collected a large-scale data set containing more than 150,000 full-text articles published in PLoS between 2006 and 2015. We divided these articles into three groups according to the ethnic backgrounds of the first and corresponding authors, obtained by Ethnea, and examined the scientific writing styles in English from a two-fold perspective of linguistic complexity: (1) syntactic complexity, including measurements of sentence length and sentence complexity; and (2) lexical complexity, including measurements of lexical diversity, lexical density, and lexical sophistication. The observations suggest marginal differences between groups in syntactical and lexical complexity.Comment: 6 figure

A protein functionalization platform based on selective reactions at methionine residues.

Nature has a remarkable ability to carry out site-selective post-translational modification of proteins, therefore enabling a marked increase in their functional diversity1. Inspired by this, chemical tools have been developed for the synthetic manipulation of protein structure and function, and have become essential to the continued advancement of chemical biology, molecular biology and medicine. However, the number of chemical transformations that are suitable for effective protein functionalization is limited, because the stringent demands inherent to biological systems preclude the applicability of many potential processes2. These chemical transformations often need to be selective at a single site on a protein, proceed with very fast reaction rates, operate under biologically ambient conditions and should provide homogeneous products with near-perfect conversion2-7. Although many bioconjugation methods exist at cysteine, lysine and tyrosine, a method targeting a less-explored amino acid would considerably expand the protein functionalization toolbox. Here we report the development of a multifaceted approach to protein functionalization based on chemoselective labelling at methionine residues. By exploiting the electrophilic reactivity of a bespoke hypervalent iodine reagent, the S-Me group in the side chain of methionine can be targeted. The bioconjugation reaction is fast, selective, operates at low-micromolar concentrations and is complementary to existing bioconjugation strategies. Moreover, it produces a protein conjugate that is itself a high-energy intermediate with reactive properties and can serve as a platform for the development of secondary, visible-light-mediated bioorthogonal protein functionalization processes. The merger of these approaches provides a versatile platform for the development of distinct transformations that deliver information-rich protein conjugates directly from the native biomacromolecules

Examining scientific writing styles from the perspective of linguistic complexity

Publishing articles in high-impact English journals is difficult for scholars around the world, especially for non-native English-speaking scholars (NNESs), most of whom struggle with proficiency in English. In order to uncover the differences in English scientific writing between native English-speaking scholars (NESs) and NNESs, we collected a large-scale data set containing more than 150,000 full-text articles published in PLoS between 2006 and 2015. We divided these articles into three groups according to the ethnic backgrounds of the first and corresponding authors, obtained by Ethnea, and examined the scientific writing styles in English from a two-fold perspective of linguistic complexity: (1) syntactic complexity, including measurements of sentence length and sentence complexity; and (2) lexical complexity, including measurements of lexical diversity, lexical density, and lexical sophistication. The observations suggest marginal differences between groups in syntactical and lexical complexity

Bonding Trends Traversing the Tetravalent Actinide Series: Synthesis, Structural, and Computational Analysis of An^IV(^Aracnac)₄ Complexes (An = Th, U, Np, Pu; ^Aracnac = Ar<i>N</i>C(Ph)CHC(Ph)<i>O</i>; Ar = 3,5‑^<i>t</i>Bu₂C₆H₃)

A series of tetravalent An­(IV) complexes with a bis-phenyl β-ketoiminate N,O donor ligand has been synthesized with the aim of identifying bonding trends and changes across the actinide series. The neutral molecules are homoleptic with the formula An­(^Aracnac)₄ (An = Th (<b>1</b>), U (<b>2</b>), Np (<b>3</b>), Pu (<b>4</b>); ^Aracnac = Ar<i>N</i>C­(Ph)­CHC­(Ph)<i>O</i>; Ar = 3,5-^<i>t</i>Bu₂C₆H₃) and were synthesized through salt metathesis reactions with actinide chloride precursors. NMR and electronic absorption spectroscopy confirm the purity of all four new compounds and demonstrate stability in both solution and the solid state. The Th, U, and Pu complexes were structurally elucidated by single-crystal X-ray diffraction and shown to be isostructural in space group <i>C</i>2/<i>c</i>. Analysis of the bond lengths reveals shortening of the An–O and An–N distances arising from the actinide contraction upon moving from <b>1</b> to <b>2</b>. The shortening is more pronounced upon moving from <b>2</b> to <b>4</b>, and the steric constraints of the tetrakis complexes appear to prevent the enhanced U–O versus Pu–O orbital interactions previously observed in the comparison of UI₂(^Aracnac)₂ and PuI₂(^Aracnac)₂ bis<i>-</i>complexes. Computational analysis of models for <b>1</b>, <b>2</b>, and <b>4</b> (<b>1a</b>, <b>2a</b>, and <b>4a</b>, respectively) concludes that both the An–O and the An–N bonds are predominantly ionic for all three molecules, with the An–O bonds being slightly more covalent. Molecular orbital energy level diagrams indicate the largest 5f-ligand orbital mixing for <b>4a</b> (Pu), but spatial overlap considerations do not lead to the conclusion that this implies significantly greater covalency in the Pu–ligand bonding. QTAIM bond critical point data suggest that both U–O/U–N and Pu–O/Pu–N are marginally more covalent than the Th analogues

Bonding Trends Traversing the Tetravalent Actinide Series: Synthesis, Structural, and Computational Analysis of An^IV(^Aracnac)₄ Complexes (An = Th, U, Np, Pu; ^Aracnac = Ar<i>N</i>C(Ph)CHC(Ph)<i>O</i>; Ar = 3,5‑^<i>t</i>Bu₂C₆H₃)

A series of tetravalent An­(IV) complexes with a bis-phenyl β-ketoiminate N,O donor ligand has been synthesized with the aim of identifying bonding trends and changes across the actinide series. The neutral molecules are homoleptic with the formula An­(^Aracnac)₄ (An = Th (<b>1</b>), U (<b>2</b>), Np (<b>3</b>), Pu (<b>4</b>); ^Aracnac = Ar<i>N</i>C­(Ph)­CHC­(Ph)<i>O</i>; Ar = 3,5-^<i>t</i>Bu₂C₆H₃) and were synthesized through salt metathesis reactions with actinide chloride precursors. NMR and electronic absorption spectroscopy confirm the purity of all four new compounds and demonstrate stability in both solution and the solid state. The Th, U, and Pu complexes were structurally elucidated by single-crystal X-ray diffraction and shown to be isostructural in space group <i>C</i>2/<i>c</i>. Analysis of the bond lengths reveals shortening of the An–O and An–N distances arising from the actinide contraction upon moving from <b>1</b> to <b>2</b>. The shortening is more pronounced upon moving from <b>2</b> to <b>4</b>, and the steric constraints of the tetrakis complexes appear to prevent the enhanced U–O versus Pu–O orbital interactions previously observed in the comparison of UI₂(^Aracnac)₂ and PuI₂(^Aracnac)₂ bis<i>-</i>complexes. Computational analysis of models for <b>1</b>, <b>2</b>, and <b>4</b> (<b>1a</b>, <b>2a</b>, and <b>4a</b>, respectively) concludes that both the An–O and the An–N bonds are predominantly ionic for all three molecules, with the An–O bonds being slightly more covalent. Molecular orbital energy level diagrams indicate the largest 5f-ligand orbital mixing for <b>4a</b> (Pu), but spatial overlap considerations do not lead to the conclusion that this implies significantly greater covalency in the Pu–ligand bonding. QTAIM bond critical point data suggest that both U–O/U–N and Pu–O/Pu–N are marginally more covalent than the Th analogues