Silver-Catalyzed Direct Nucleophilic Cyclization: Enantioselective Synthesis of C-C Axially Chiral 2-Arylindoles.

Atropisomeric indoles widely exist in natural products, pharmaceuticals, functional materials, and catalysts for their featured biological activities, photoelectric properties, and catalytic activities, while facile and construction of this motif remains underexplored. Herein, we report a chiral silver phosphate-catalyzed direct 5-- nucleophilic cyclization of 2-alkynylanilins under mild conditions, affording various C-C axially chiral 2-arylindoles in high to excellent yields and enantioselectivities. Control experiments implied the cooperative catalysis of AgOAc and chiral phosphoric acid, wherein the former accelerated the desired transformation while the latter improved the enantioselectivity.

Transcriptome Analysis of Beet Webworm Shows That Histone Deacetylase May Affect Diapause by Regulating Juvenile Hormone.

The beet webworm ( L.) is an important agricultural pest and can tolerate harsh environmental conditions by entering diapause. The diapause mechanism of beet webworm is unknown.

Tetracycline removal in granulation: Influence of extracellular polymers substances, structure, and metabolic function of microbial community.

Tetracycline is a potentially hazardous residual antibiotic detected in various sewages. High concentration (mg/L) of tetracycline is found in pharmaceutical/hospital wastewater and wastewater derived from livestock and poultry. So far, only antibiotics in μg/L level have been reported in granulation of aerobic sludge during wastewater treatment, but its effects in high concentration are rarely reported.

[Effects of community succession on plant reproductive allocation and ecological stoichiometry for two dominant species in the Hulunbuir Grassland, China].

To explore the physiological and ecological adaptability of different dominant species during grassland community succession, we measured soil nutrients, plant biomass and C, N and P contents of two dominant species using the method of spatial sequences instead of chronosequences in the successive series of Agropyron michnoi community - A. michnoi + A. cristatam community - A.

A 2-Fold Interpenetrated Nitrogen-Rich Metal-Organic Framework for Rapid and Selective Adsorption of Congo Red.

A new metal-organic framework was prepared based on a mixed ligand system of the designed nitrogen-rich 3,6-bis(2-methylimidazole)pyrimidine (b2mpm) and benzophenone 4,4'-dicarboxylic acid (Hbpndc). The prepared material shows a three-dimensional 2-fold interpenetrated framework and features rectangular channels decorated with nitrogen sites. Thanks to the abundant hydrogen bonding and π-π stacking interactions, the titled material can rapidly adsorb Congo red (CR) and presents ultrahigh adsorption capacity (2348 mg g).

Enhanced nitrogen removal in an aerobic granular sequencing batch reactor under low DO concentration: Role of extracellular polymeric substances and microbial community structure.

In this study, the role of extracellular polymeric substances (EPSs) in nitrogen removal and the microbial community structure of aerobic granular sludge (AGS) were analyzed under different dissolved oxygen (DO) conditions (6-7, 4-5, and 2-3 mg·L). The EPSs transported and retained nitrogen in the denitrification process, and the total inorganic nitrogen (TIN) in the EPSs decreased from 6.09 to 5.

Insight into the roles of tightly and loosely bound extracellular polymeric substances on a granular sludge in ammonium nitrogen removal.

To explicitly understand the function of extracellular polymeric substances in the treatment of ammonium-nitrogen-rich wastewater using aerobic granular sludge, the three forms of nitrogen (ammonium, nitrite and nitrate nitrogen) contained in tightly and loosely bound extracellular polymeric substances were analyzed. The three forms of nitrogen were monitored in the tightly and loosely bound extracellular polymeric substances in aerobic granular sludge after adsorption. The ammonium nitrogen contained in the extracellular polymeric substances was distributed in both the tightly and loosely bound forms and decreased gradually as the aeration time increased.

Design and construction of linear laser encoders that possess high tolerance of mechanical runout.

A linearly diffracted laser encoder that has high tolerance of head-to-scale misalignment and a high signal-to-noise ratio is described. The preservation of parallelism between the incident and the diffracted beams, which can be attributed to a built-in folded 1x telescope, allows for the high alignment tolerance. It can be shown that, by coupling this newly developed circular polarization interferometer configuration with grating scale geometry optimization, one can eliminate the problems associated with signal distortion that arise from various efficiencies of the p- and the s-polarized light beams and obtain a high signal-to-noise ratio.