Enantioconvergent and diastereoselective synthesis of atropisomeric hydrazides bearing a cyclic quaternary stereocenter through ternary catalysis.

An efficient and highly enantioconvergent and diastereoselective ternary catalysis in a one-pot process is reported, which represents an integrated strategy for the synthesis of atropisomeric hydrazides with defined vicinal central and axial chirality from readily available racemic α-amino-ynones, azodicarboxylates, and Morita-Baylis-Hillman (MBH) carbonates. This method utilizes -generated racemic pyrrolin-4-ones hydroamination of racemic α-amino-ynones by AuCl catalysis as a novel and versatile C1 synthon, which engage commercially available azodicarboxylates to generate amination products in high yields and uniformly excellent enantioselectivities under the catalysis of a chiral phosphoric acid. Following amination, -alkylation catalyzed by diastereoselective organocatalyst afforded axially chiral hydrazides with excellent diastereoselectivities (>98 : 2 dr).

Kinetic Resolution of Acyclic Tertiary Propargylic Alcohols by NHC-Catalyzed Enantioselective Acylation.

We report herein an efficient NHC-catalyzed kinetic resolution of acyclic tertiary propargylic alcohols that provides them in high to excellent enantioselectivity. This is the first example of kinetic resolution realized by enantioselective acylation. The recovered enantioenriched alcohols can be facilely converted into other valuable compounds such as densely functionalized tertiary alcohols and carbmates in high yields and excellent stereopurity.

Olver plasmon: an accelerating surface wave with various orders.

In this Letter, we introduce a new, to the best of our knowledge, class of accelerating surface plasmonic wave: the Olver plasmon. Our research reveals that such a surface wave propagates along self-bending trajectories at the silver-air interface with various orders, among which Airy plasmon is regarded as the zeroth-order one. We demonstrate a plasmonic autofocusing hot-spot by the interference of Olver plasmons and the focusing properties can be controlled.

Autofocusing self-imaging: symmetric Pearcey Talbot-like effect.

The Talbot-like effect of symmetric Pearcey beams (SPBs) is presented numerically and experimentally in the free space. Owing to the Talbot-like effect, the SPBs have the property of periodic, multiple autofocusing and self-healing. Meanwhile, the focusing positions and focusing times of SPBs are controlled by the beam shift factor and the distribution factors.

Airy-Talbot plasmon: an accelerating self-imaging surface wave.

In this Letter, a new class of an accelerating self-imaging surface plasmonic wave, the Airy-Talbot plasmon, is introduced for the first time, to the best of our knowledge. Our research shows that such a surface wave propagates at the interface between metal (silver) and a dielectric material (air) and causes a strong interference along curved trajectories, which generates the Talbot effect in the surface. The propagation properties have potential value in nanoscale plasmonic devices.

[Correlation of VEGF expression with microvessel and microlymphatic density in sinonasal squamous cell carcinoma].

Objective: To study the expression of VEGF in sinonasal squamous cell carcinoma and its correlations with microvessel density (MVD), microlymphatic vessel density (MLVD).

Method: The expression of VEGF, MVD and MLVD in 41 cases of sinonasal squamous cell carcinoma were detected by immunohistochemical technique.

Result: In the sinonasal squamous cell carcinoma, the positive rate of VEGF was 82.

Photoinduced chlorine atom-transfer cyclization/photohydrolysis of 3-acyl-2-chloro-N-(ω-phenylalkynyl)pyrroles: a one-pot synthesis of benzoyl-substituted fused pyrroles.

A one-pot synthesis of benzoyl-substituted fused pyrroles or indoles in moderate to high yields has been achieved by the photocyclization/photohydrolysis reactions of N-(ω-phenylalkynyl)-2-chloropyrrole-3-carbaldehydes or 3-acyl-N-(ω-phenylbutynyl)-2-haloindoles in wet acetone. The formation of all these products could be inferred by a two-step reactions, namely, photoinduced chlorine atom-transfer cyclization and subsequent photohydrolysis.

Photoinduced cyclization of 3-acyl-2-halo-1-[(ω-phenylethynyl)alkyl]indoles to azaheterocyclo[1,2,3-lm]-fused benzo[c]carbazoles.

A one-pot synthesis of azaheterocyclo[1,2,3-lm]-fused benzo[c]carbazoles (2 and 3) has been developed by photocyclization of 3-acyl-2-halo-1-[(ω-phenylethynyl)alkyl] indoles (1) in good to excellent yields. All products are formed from 1 via two sequential photocyclization reactions. Two products, 9-chloro-7,8-dihydro-6H-benzo[c]pyrido[1,2,3-lm]carbazole (2a-h) and 7,8-dihydro-6H-benzo[c]pyrido[1,2,3-lm]carbazole (3a-h), are produced in the photocyclization of 2-halo-1-[(ω-phenylethynyl)alkyl]indole-3-carbaldehydes (1a-h).

Solid phase extraction of trace Hg(II) on silica gel modified with 2-(2-oxoethyl)hydrazine carbothioamide and determination by ICP-AES.

In this work, a new 2-(2-oxoethyl)hydrazine carbothioamide modified silica gel (SG-OHC) sorbent was prepared and applied for preconcentration of trace mercury(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimization of some analytical parameters affecting the adsorption of the analyte such as acidity, shaking time, sample flow rate and volume, eluent condition, and interfering substances were investigated. At pH 3, the maximum static adsorption capacity of Hg(II) onto the SG-OHC was 37.

[Expression of STAT6 in human nasal polyps and the relation between STAT6 and eosinophil infiltration].

Objective: To study the distribution and expression of STAT6 and to examine the suggested roles of STAT6 in the pathogenesis of eosinophil infiltration in nasal polyps and to evaluate the role of STAT6 in the pathogenesis of nasal polyps.

Method: All selected cases met the enrollment criteria. Thirty samples of nasal polyps were obtained from patients undergoing nasal polypectomy, and 10 samples of inferior turbinate tissues were from patients undergoing nasal septal reconstruction.

Silica gel modified with 1-(2-aminoethyl)-3-phenylurea for selective solid-phase extraction and preconcentration of Sc(III) from environmental samples.

A new method that utilizes 1-(2-aminoethyl)-3-phenylurea-modified silica gel as a solid-phase extractant has been developed for preconcentration of trace Sc(III) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace level of Sc(III) were optimized using batch and column procedures in detail. The optimum pH value for the separation of Sc(III) on the new sorbent was 4 and complete elution of Sc(III) from the sorbent surface was carried out using 1.

Preconcentration of Cu(II), Fe(III) and Pb(II) with 2-((2-aminoethylamino)methyl)phenol-functionalized activated carbon followed by ICP-OES determination.

A procedure for separation and preconcentration trace amount of Cu(II), Fe(III) and Pb(II) by 2-((2-aminoethylamino)methyl)phenol-functionalized activated carbon (AC-AMP) packed column has been proposed. Under the optimized conditions (pH 4, flow rate 2.0 mL min(-1)), Cu(II), Fe(III) and Pb(II) were retained on the column, then quantitatively eluted by 2 mL 1 mol L(-1) nitric acid solution and determined by inductively coupled plasma-optical emission spectrometry (ICP-OES).

1-(2-Formamidoethyl)-3-phenylurea functionalized activated carbon for selective solid-phase extraction and preconcentration of metal ions.

A novel method that utilizes 1-(2-formamidoethyl)-3-phenylurea-modified activated carbon (AC-1-(2-formamidoethyl)-3-phenylurea) as a solid-phase extractant has been developed for simultaneous preconcentration of trace Cr(III), Cu(II), Fe(III) and Pb(II) prior to the measurement by inductively coupled plasma atomic emission spectrometry (ICP-AES). Experimental conditions for effective adsorption of trace levels of Cr(III), Cu(II), Fe(III) and Pb(II) were optimized using batch and column procedures in detail. The optimum pH value for the separation of metal ions simultaneously on the new sorbent was 4.

Chemically modified activated carbon with 1-acylthiosemicarbazide for selective solid-phase extraction and preconcentration of trace Cu(II), Hg(II) and Pb(II) from water samples.

A new sorbent 1-acylthiosemicarbazide-modified activated carbon (AC-ATSC) was prepared as a solid-phase extractant and applied for removing of trace Cu(II), Hg(II) and Pb(II) prior to their determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The separation/preconcentration conditions of analytes were investigated, including effects of pH, the shaking time, the sample flow rate and volume, the elution condition and the interfering ions. At pH 3, the maximum static adsorption capacity of Cu(II), Hg(II) and Pb(II) onto the AC-ATSC were 78.

Photoinduced Intramolecular addition of 3-acyl-2-haloindoles to alkenes.

1,2-Fused indoles and pyrroles were prepared via an efficient intramolecular photoaddition reaction of 1-(omega-alkenyl)-2-haloindole-3-carbaldehydes and 1-(omega-alkenyl)-2-chloropyrrole-3-carbaldehydes. The presence of an acyl group was necessary for the photocyclization reactions. The halogen-atom-retained exo- and endo-cyclization products were generally produced with results similar to those of an atom-transfer cyclization reaction.