Chiral Bifunctional Phosphine Ligand Enables Asymmetric Trapping of Catalytic Vinyl Gold Carbene Species

Bifunctional ligand-enabled cooperative gold catalysis accelerates nucleophilic attacks and offers a versatile strategy to achieve asymmetric gold catalysis. Distinct from the prior studies employing alkyne/allene as the electrophilic site, this work engages an in situ-generated alkenyl/acyl gold carbene in a ligand-facilitated attack by an alcoholic nucleophile. With an amide-functionalized chiral binaphthylphosphine ligand, γ-alkoxy-α,β-unsaturated imides are formed with excellent enantiomeric excesses. The intermediacy of a carbene species is supported by its alternative access via dediazotization. The reaction tolerates a broad range of alcohols and can accommodate dienynamide substrates, in addition to arylenynamides. This work avails a versatile strategy to enrich gold chemistry and achieve challenging enantioselective gold catalysis via ligand-facilitated enantioselective trapping of reactive intermediates

Isocyanate Formation from Reactions of Early Lanthanide Metal Atoms with NO and CO in Solid Argon

The reactions of early lanthanide metal atoms (Ce, Pr, and Nd) with carbon monoxide and nitric oxide mixtures are studied by infrared absorption spectroscopy in solid argon. The reaction intermediates and products are identified via isotopic substitution as well as theoretical frequency calculations. The results show that the reactions proceed with the initial formation of inserted NLnO molecules, which subsequently react with CO to form the NLnO­(CO) complexes on annealing. The NLnO­(CO) complexes further isomerize to the more stable isocyanate OLnNCO species under UV light excitation

Clinicopathological and Prognostic Significance of CD24 Overexpression in Patients with Gastric Cancer: A Meta-Analysis

<div><p>Objective</p><p>The prognostic significance of CD24 expression for survival in patients with gastric cancer remains controversial. We conducted a meta-analysis to investigate the impact of CD24 expression on clinicopathological features and survival outcomes in gastric cancer.</p><p>Methods</p><p>A comprehensive literature search of the electronic databases PubMed, Embase, Web of Science and China National Knowledge Infrastructure (CNKI; up to April 8, 2014) was performed for relevant studies using multiple search strategies. Correlations between CD24 expression and clinicopathological features and overall survival (OS) were analyzed.</p><p>Results</p><p>A total of 1,041 patients with gastric cancer from 9 studies were included. The pooled odds ratios (ORs) indicated CD24 expression was associated with tumor depth (OR = 0.45, 95% confidence interval [CI]  = 0.32–0.63; P<0.00001), status of lymph nodes (OR = 0.40, 95% CI = 0.25–0.64; P = 0.0001) and tumor node metastasis (TNM) stage (OR = 0.56, 95% CI = 0.41–0.77; P = 0.0003). The pooled hazard ratio (HR) for OS showed overexpression of CD24 reduced OS in gastric cancer (HR = 1.99, 95% CI = 1.29–3.07, P = 0.002). Whereas, combined ORs showed that CD24 expression had no correlation with tumor differentiation or Lauren classifications.</p><p>Conclusion</p><p>CD24 overexpression in patients with gastric cancer indicated worse survival outcomes and was associated with common clinicopathological poor prognostic factors.</p></div

Forest plot of hazard ratio for overall survival of patients with gastric cancer.

<p>The squares and horizontal lines correspond to the study- specific HR and 95% CI. The area of the squares reflects the study-specific weight (inverse of the variance). The diamonds represent the pooled HR and 95% CI. The solid vertical line is at the null value (HR = 1). The pooled HR for OS showed overexpression of CD24 reduced OS in gastric cancer (HR = 1.99, 95%CI 1.29–3.07, P = 0.002).</p

Begg's funnel plot of publication bias of hazard ratio for overall survival in the meta-analysis.

<p>The funnel plot displays log HR against its standard error (s.e.) for each individual study. The horizontal line represents the estimate of the overall HR, with the dash lines indicating the expected 95% CI for a given standard error. No evidence of publication bias was observed in the meta-analysis.</p

Flow chart for selection of studies.

<p>Excluded studies with the reasons for exclusion were listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0114746#pone.0114746.s001" target="_blank">S1 Table</a>.</p

Characteristics of eligible studies.

<p><i>IHC</i> Immunohistochemistry.</p><p>Characteristics of eligible studies.</p

Supplementary_Fig – Supplemental material for Delayed Recovery in Pediatric Sudden Sensorineural Hearing Loss Predicted via Magnetic Resonance Imaging

<p>Supplemental material, Supplementary_Fig for Delayed Recovery in Pediatric Sudden Sensorineural Hearing Loss Predicted via Magnetic Resonance Imaging by Xuan Wu, Hongyan Jiang, Lanying Wen, Ling Zong and Kaitian Chen in Annals of Otology, Rhinology & Laryngology</p

Photoassisted Homocoupling of Methyl Iodide Mediated by Atomic Gold in Low-Temperature Neon Matrix

Infrared spectroscopy and density functional theory calculations showed that the gold complexes [CH₃–Au–I] and [(CH₃)₂–Au–I₂], in which one and two CH₃I molecule(s), respectively, are oxidatively adsorbed on the Au atoms, are formed in a solid neon matrix via reactions between laser-ablated gold atoms and CH₃I. Global reaction route mapping calculations revealed that the heights of the activation barriers for the sequential oxidative additions to produce [CH₃–Au–I] and [(CH₃)₂–Au–I₂] are 0.53 and 1.00 eV, respectively, suggesting that the reactions proceed via electronically excited states. The reductive elimination of ethane (C₂H₆) from [(CH₃)₂–Au–I₂] leaving AuI₂ was hindered by an activation barrier as high as 1.22 eV but was induced by visible-light irradiation on [(CH₃)₂–Au–I₂]. These results demonstrate that photoassisted homocoupling of CH₃I is mediated by Au atoms via [(CH₃)₂–Au–I₂] as an intermediate

Novel Pillar[5]arene-Based Dynamic Polyrotaxanes Interlocked by the Quadruple Hydrogen Bonding Ureidopyrimidinone Motif

Novel dynamic polyrotaxanes constructed from pillar[5]arenes as wheels and diamines as axles have been successfully synthesized in good yield using quadruple hydrogen bonding ureidopyrimidinone (UPy) motifs, which play a dual role as the end-capping and interlocking units. The present study is the first example of noncovalent bonded dynamic polyrotaxanes constructed by multiple hydrogen bonding interactions