Gender bias in sentiment analysis

This is an accepted manuscript of an article published by Emerald Publishing Limited in Online Information Review on 14/02/2018, available online: https://doi.org/10.1108/OIR-05-2017-0139 The accepted version of the publication may differ from the final published version.Purpose: To test if there are biases in lexical sentiment analysis accuracy between reviews authored by males and females. Design: This paper uses datasets of TripAdvisor reviews of hotels and restaurants in the UK written by UK residents to contrast the accuracy of lexical sentiment analysis for males and females. Findings: Male sentiment is harder to detect because it is less explicit. There was no evidence that this problem could be solved by gender-specific lexical sentiment analysis. Research limitations: Only one lexical sentiment analysis algorithm was used. Practical implications: Care should be taken when drawing conclusions about gender differences from automatic sentiment analysis results. When comparing opinions for product aspects that appeal differently to men and women, female sentiments are likely to be overrepresented, biasing the results. Originality/value: This is the first evidence that lexical sentiment analysis is less able to detect the opinions of one gender than another

Superposition of the active site of DPP-4-ligand complex structures deposited in Protein databank (ice blue) and the re-refined and re-built (gold). A σ_A-weighted <i>F</i>_O-<i>F</i>_C omit map (3.0σ, in brown mesh) is superposed on the inhibitors.

<p>(a) Sitagliptin <b>1</b>. (b) Linagliptin <b>2</b>. (c) Alogliptin <b>3</b>. (d) Teneligliptin <b>4</b>.</p

Comparative Binding Analysis of Dipeptidyl Peptidase IV (DPP-4) with Antidiabetic Drugs – An <i>Ab Initio</i> Fragment Molecular Orbital Study - Fig 3

<p>Binding modes of each inhibitor [(a) sitagliptin <b>1</b>; (b) linagliptin <b>2</b>; (c) alogliptin <b>3</b>; (d) teneligliptin <b>4</b>] in the active site of DPP-4 complex structure. S₂ ext. (S₂ extensive) subsite constructed by Val207, Ser209, Phe357, Arg358, in yellow. S₂ subsite constructed by Arg125, Phe357, Arg358, Glu205, Glu206, Arg669, in light purple. S₁ subsite constructed by Ser630, Val656, Trp659, Tyr662, Tyr666, Val711, Asn710, in orange. subsite constructed by Phe357, Tyr547, Pro550, Ser630, Tyr631, Tyr666, in light green. subsite constructed by Tyr547, Trp629, Ser630, His740, in cyan.</p

Correlation between number of non-hydrogen atoms of ligands and the interfacial buried surface area with chain A of DPP-4.

<p>The correlation coefficient is 0.97.</p

Origin of Stereoselectivity and Substrate/Ligand Recognition in an FAD-Dependent <i>R</i>‑Selective Amine Oxidase

Elucidation of the molecular mechanism of amine oxidases (AOx) will help to extend their reactivity by rational design and their application to deracemization of various amine compounds. To date, several studies have been performed on <i>S</i>-selective AOx, but relatively few have focused on <i>R</i>-selective AOx. In this study, we sought to elucidate the mechanism of pkAOx, an <i>R</i>-selective AOx that we designed by introducing the Y228L and R283G mutations into d-amino acid oxidase from pig kidney. Four crystal structures of the substrate-bound protein and first-principles calculations based on the correlated fragment molecular orbital (FMO) indicated that two aromatic residues, Tyr224 and Phe242, form stable π–π stacking interaction with substrates. Enzyme kinetics also supported the importance of Tyr224 in catalysis: the <i>k</i>_cat/<i>K</i>_m value of the Y224L mutant was reduced by 300-fold than that of wild-type (WT) when utilizing either (<i>R</i>)-methylbenzylamine [(<i>R</i>)-MBA] or (<i>R</i>)-1-(2-naphthyl)­ethylamine [(<i>R</i>)-NEA] as the substrate. On the other hand, several Phe242 mutants exhibited higher reactivity toward (<i>R</i>)-NEA than the WT enzyme. In addition, FMO analysis indicated that pkAOx forms ∼13 kcal/mol more stable interaction with (<i>R</i>)-MBA than with (<i>S</i>)-MBA; this energy difference contributes to specific recognition of (<i>R</i>)-MBA in the racemate. Through the present study, we clarified three features of pkAOx: the roles of Tyr224 and Phe242 in catalysis, the origin of high stereoselectivity, and the potential to extend its reactivity toward amine compounds with bulky groups

Benchmark Analysis of Native and Artificial NAD⁺‑Dependent Enzymes Generated by a Sequence-Based Design Method with or without Phylogenetic Data

The expansion of protein sequence databases has enabled us to design artificial proteins by sequence-based design methods, such as full-consensus design (FCD) and ancestral-sequence reconstruction (ASR). Artificial proteins with enhanced activity levels compared with native ones can potentially be generated by such methods, but successful design is rare because preparing a sequence library by curating the database and selecting a method is difficult. Utilizing a curated library prepared by reducing conservation energies, we successfully designed two artificial l-threonine 3-dehydrogenases (SDR-TDH) with higher activity levels than native SDR-TDH, FcTDH-N1, and AncTDH, using FCD and ASR, respectively. The artificial SDR-TDHs had excellent thermal stability and NAD⁺ recognition compared to native SDR-TDH from <i>Cupriavidus necator</i> (CnTDH); the melting temperatures of FcTDH-N1 and AncTDH were about 10 and 5 °C higher than that of CnTDH, respectively, and the dissociation constants toward NAD⁺ of FcTDH-N1 and AncTDH were 2- and 7-fold lower than that of CnTDH, respectively. Enzymatic efficiency of the artificial SDR-TDHs were comparable to that of CnTDH. Crystal structures of FcTDH-N1 and AncTDH were determined at 2.8 and 2.1 Å resolution, respectively. Structural and MD simulation analysis of the SDR-TDHs indicated that only the flexibility at specific regions was changed, suggesting that multiple mutations introduced in the artificial SDR-TDHs altered their flexibility and thereby affected their enzymatic properties. Benchmark analysis of the SDR-TDHs indicated that both FCD and ASR can generate highly functional proteins if a curated library is prepared appropriately

Regiocomplementary Cycloaddition Reactions of Boryl- and Silylbenzynes with 1,3-Dipoles: Selective Synthesis of Benzo-Fused Azole Derivatives

Benzo-fused nitrogen-containing heterocycles are abundant in biologically active compounds. One of the most important methods for preparing such heterocycles is the (3 + 2) cycloaddition reaction of benzynes with 1,3-dipolar compounds. However, the reactions of unsymmetrically substituted benzynes generally show low selectivity and hence yield mixtures of two regioisomers. In this paper, we describe the synthesis of both regioisomers of multisubstituted benzo-fused azole derivatives such as benzotriazoles, 1<i>H</i>-indazoles, and benzo­[<i>d</i>]­isoxazoles through the regiocomplementary (3 + 2) cycloaddition reactions of 3-boryl- and 3-silylbenzynes with 1,3-dipoles. The improved generation of 3-borylbenzynes from new precursors was one of the most important results of this work, which produced the successful (3 + 2) cycloaddition reactions with exclusive and proximal selectivities. On the other hand, similar reactions of 3-silylbenzynes selectively afforded distal cycloadducts. Analysis of the reaction pathways of these amazing regioselectivities by density functional theory calculations revealed that the (3 + 2) cycloadditions of borylbenzynes are controlled by the electrostatic effect of the boryl group, while those of silylbenzynes are controlled mainly by the steric effect of the bulky silyl groups that produced electrostatically unfavorable adducts via anomalous transition states

25<i>S</i>‑Adamantyl-23-yne-26,27-dinor-1α,25-dihydroxyvitamin D₃: Synthesis, Tissue Selective Biological Activities, and X‑ray Crystal Structural Analysis of Its Vitamin D Receptor Complex

Both 25<i>R</i>- and 25<i>S</i>-25-adamantyl-23-yne-26,27-dinor-1α,25-dihydroxy­vitamin D₃ (<b>4a</b> and <b>4b</b>) were stereoselectively synthesized by a Pd(0)-catalyzed ring closure and Suzuki–Miyaura coupling between enol-triflate <b>7</b> and alkenyl-boronic ester <b>8</b>. The 25<i>S</i> isomer (<b>4b</b>) showed high vitamin D receptor (VDR) affinity (50% of that of the natural hormone 1α,25-dihydroxy­vitamin D₃, <b>1</b>) and transactivation potency (kidney HEK293, 90%). In endogenous gene expression, it showed high cell-type selectivity for kidney cells (HEK293, CYP24A1 160% of <b>1</b>), bone cells (MG63, osteocalcin 64%), and monocytes (U937, CAMP 96%) over intestine (SW480, CYP24A1 8%) and skin (HaCaT, CYP24A1 7%) cells. The X-ray crystal structural analysis of <b>4b</b> in complex with rat VDR-ligand binding domain (LBD) showed the highest Cα positional shift from the <b>1/</b>VDR-LBD complex at helix 11. Helix 11 of the <b>4b</b> and <b>1</b> VDR-LBD complexes also showed significant differences in surface properties. These results suggest that <b>4b</b> should be examined further as another candidate for a mild preventive osteoporosis agent

25<i>S</i>‑Adamantyl-23-yne-26,27-dinor-1α,25-dihydroxyvitamin D₃: Synthesis, Tissue Selective Biological Activities, and X‑ray Crystal Structural Analysis of Its Vitamin D Receptor Complex

Both 25<i>R</i>- and 25<i>S</i>-25-adamantyl-23-yne-26,27-dinor-1α,25-dihydroxy­vitamin D₃ (<b>4a</b> and <b>4b</b>) were stereoselectively synthesized by a Pd(0)-catalyzed ring closure and Suzuki–Miyaura coupling between enol-triflate <b>7</b> and alkenyl-boronic ester <b>8</b>. The 25<i>S</i> isomer (<b>4b</b>) showed high vitamin D receptor (VDR) affinity (50% of that of the natural hormone 1α,25-dihydroxy­vitamin D₃, <b>1</b>) and transactivation potency (kidney HEK293, 90%). In endogenous gene expression, it showed high cell-type selectivity for kidney cells (HEK293, CYP24A1 160% of <b>1</b>), bone cells (MG63, osteocalcin 64%), and monocytes (U937, CAMP 96%) over intestine (SW480, CYP24A1 8%) and skin (HaCaT, CYP24A1 7%) cells. The X-ray crystal structural analysis of <b>4b</b> in complex with rat VDR-ligand binding domain (LBD) showed the highest Cα positional shift from the <b>1/</b>VDR-LBD complex at helix 11. Helix 11 of the <b>4b</b> and <b>1</b> VDR-LBD complexes also showed significant differences in surface properties. These results suggest that <b>4b</b> should be examined further as another candidate for a mild preventive osteoporosis agent

Synthetic Small Molecules Derived from Natural Vitamin K Homologues that Induce Selective Neuronal Differentiation of Neuronal Progenitor Cells

We synthesized new vitamin K₂ analogues with ω-terminal modifications of the side chain and evaluated their selective differentiation of neuronal progenitor cells into neurons in vitro. The result of the assay showed that the menaquinone-3 analogue modified with the <i>m</i>-methylphenyl group had the most potent activity, which was twice as great as the control. This finding indicated that it is possible to obtain much more potent compounds with modification of the structure of vitamin K₂