Was the first industrial revolution a conjuncture in the history of the world economy?

Quantitative analysis of flavonoids in flower petals of Nymphaea ‘King of Siam’. (DOCX 18 kb

Generation of Indeno[1,2-<i>c</i>]pyrroles via a Pd-Catalyzed Reaction of 2-Alkynylbromobenzene with Propargylic Sulfonamide

A novel route for the efficient assembly of indeno[1,2-<i>c</i>]pyrrole derivatives via a palladium-catalyzed tandem reaction of 2-alkynylbromobenzene with propargylic sulfonamide is reported. The starting materials are easily available, and the reaction proceeds smoothly with good functional group tolerance

Generation of Indeno[1,2-<i>c</i>]pyrroles via a Pd-Catalyzed Reaction of 2-Alkynylbromobenzene with Propargylic Sulfonamide

A novel route for the efficient assembly of indeno[1,2-<i>c</i>]pyrrole derivatives via a palladium-catalyzed tandem reaction of 2-alkynylbromobenzene with propargylic sulfonamide is reported. The starting materials are easily available, and the reaction proceeds smoothly with good functional group tolerance

A New Insight into Palladium-Catalyzed Reaction of 2-Alkynylphenol with Carbon Monoxide

A novel and efficient pathway for the generation of 3-(benzofuran-3-ylmethylene)benzofuran-2(3<i>H</i>)-ones via a palladium-catalyzed carbonylative reaction of 2-alkynylphenol with carbon monoxide is described. The reaction proceeds through a double insertion of triple bonds during the reaction process. The products are obtained in good yields with high selectivity. A one-pot synthesis starting from 2-iodophenol and alkyne is presented as well

Synthesis of Tetrahydropyridine Derivatives through a Reaction of 1,6-Enynes, Sulfur Dioxide, and Aryldiazonium Tetrafluoroborates

Sulfonated tetrahydropyridine derivatives are accessed through a radical reaction of 1,6-enynes, sulfur dioxide, and aryldiazonium tetrafluoroborates under mild conditions. Sulfonated pyrrolidine can be generated when terminal alkyne is used as the substrate. This reaction proceeds efficiently in dichloroethane without the addition of any catalysts or additives, providing sulfonated tetrahydropyridine derivatives in moderate to good yields. During this transformation, aryldiazonium tetrafluoroborates cooperate with DABCO·(SO₂)₂ leading to sulfonyl radicals, which initiate the radical cyclization process. Two molecules of aryldiazonium tetrafluoroborates are involved in the reaction

Assembly of Chitin Nanofibers into Porous Biomimetic Structures via Freeze Drying

The intricate hierarchical architectures in natural creatures are usually derived from assembly of molecular building blocks into nanoscale structures that then organize into micro- and macroscopic sizes. An example is the complex structure in arthropods (crustaceans, insects) constructed primarily of chitin. Because of chitin’s inherent insolubility in common solvents, processes for mimicking the fascinating natural chitin-based nanostructures are still at an early stage of development. Here, we present a facile freeze-drying approach to assemble chitin nanofibers (20 nm diameter) into a variety of structures whose size and morphology are tunable by adjusting freezing temperature and heat transfer characteristics. We show that reducing the freezing rate allows controllable formation of structures ranging from oriented sheets to three-dimensional aperiodic nanofiber networks that mimic the size and interconnectivity of the white <i>Cyphochilus</i> beetle cuticle. The formation of nanofibrous structures is not predicted by the widely used particle encapsulation model of freeze-drying. We reason that this structure occurs due to a combination of attractive interactions of the nanofibers and a slow freezing rate that encapsulates and preserves the network structure. The method outlined here is likely applicable to creating fine nanofibrous structures with other polymers and materials classes with size ranges useful in diverse applications such as tissue engineering, filtration, and energy storage

Palladium-Catalyzed Direct C–H Functionalization of Indoles with the Insertion of Sulfur Dioxide: Synthesis of 2‑Sulfonated Indoles

A palladium-catalyzed direct C–H bond sulfonylation of indoles with the insertion of sulfur dioxide is achieved through a three-component reaction of 1-(pyridin-2-yl)­indoles, DABCO·(SO₂)₂, and aryldiazonium tetrafluoroborates under mild conditions. Diverse 2-sulfonated indoles are generated by using 10 mol % of palladium­(II) bromide as the catalyst at room temperature. This synthetic approach is efficient by merging palladium catalysis and insertion of sulfur dioxide via a radical process. 2-Pyrimidinyl can be used as the directing group well as for the C–H bond sulfonylation. Additionally, the directing group can be easily removed

Association of Gln27Glu and Arg16Gly Polymorphisms in Beta2-Adrenergic Receptor Gene with Obesity Susceptibility: A Meta-Analysis

<div><p>Background</p><p>The beta2-adrenergic receptor (ADRB2) gene polymorphism has been implicated in susceptibility to obesity, but study results are still controversial.</p><p>Objective</p><p>The present meta-analysis is performed to determine whether there are any associations between the Gln27Glu (rs1042714) or the Arg16Gly (rs1042713) polymorphisms in ADRB2 and obesity susceptibility.</p><p>Methods</p><p>The PubMed (1950–2014), Embase (1974–2014), and China National Knowledge Infrastructure (CNKI, 1994–2014) databases were searched using the search terms (“Beta2-adrenergic receptor”, “β2-adrenergic receptor” or “ADRB2”), “polymorphism,” and “obesity”. Fixed- or random-effects pooled measures were determined on the bias of heterogeneity tests across studies. Publication bias was examined by Egger's test and the modified Begg's test.</p><p>Results</p><p>Eighteen published articles were selected for meta-analysis. Overall analyses showed that rs1042714 (Gln27Glu) was associated with significantly increased obesity risk in the heterozygote model (Gln/Glu vs. Gln/Gln: OR: 1.16, 95% CI: 1.04–1.30, <i>I</i>² = 49%, P = 0.009) and the dominant model (Gln/Glu + Glu/Glu vs. Gln/Gln: OR: 1.2, 95% CI: 1.00–1.44, <i>I</i>² = 55%, P = 0.04), whereas no significant association was found in the other models for rs1042714. Also, no significant association was found between the rs1042713 (Arg16Gly) gene polymorphism and the risk of obesity in all genetic models. In addition, neither rs1042713 (Arg16Gly) nor rs1042714 (Gln27Glu) showed any significant association with obesity susceptibility when the population were stratified based on gender.</p><p>Conclusion</p><p>Our meta-analysis revealed that the rs1042714 (Gln27Glu) polymorphism is associated with obesity susceptibility. However, our results do not support an association between rs1042713 (Arg16Gly) polymorphisms and obesity in the populations investigated. This conclusion warrants confirmation by more case-control and cohort studies.</p></div

An Unexpected Silver Triflate Catalyzed Reaction of 2-Alkynylbenzaldehyde with 2-Isocyanoacetate

An unexpected silver triflate catalyzed reaction of 2-alkynylbenzaldehyde with 2-isocyanoacetate provides an efficient route for the generation of isoquinolines. The reaction proceeds smoothly in air under mild conditions with high efficiency

Distributions of ADRB2 Gln27/Glu and Arg16/Gly genotypes of eligible studies included in the meta-analysis.

<p>ADRB2, Beta 2-adrenergic receptor gene; Gln27Glu (rs1042714), at codon 27; Arg16Gly (rs1042713), at codon 16.</p