Dearomative hydroamination of heteroarenes catalyzed by the phenolate photocatalyst.

Dearomative functionalization of heteroarenes offers an attractive and sustainable approach for the rapid construction of complex 3D heterocyclic scaffolds from planar structures. Despite progress in this field, dearomative amination of heteroarenes a radical anion intermediate remains a challenge. Here, we report a photoredox-catalyzed dearomative hydroamination of heteroarenes with hydrazodiformates under mild and transition-metal-free reaction conditions.

Multi-targeted interference-free determination of ten β-blockers in human urine and plasma samples by alternating trilinear decomposition algorithm-assisted liquid chromatography-mass spectrometry in full scan mode: comparison with multiple reaction monitoring.

β-blockers are the first-line therapeutic agents for treating cardiovascular diseases and also a class of prohibited substances in athletic competitions. In this work, a smart strategy that combines three-way liquid chromatography-mass spectrometry (LC-MS) data with second-order calibration method based on alternating trilinear decomposition (ATLD) algorithm was developed for simultaneous determination of ten β-blockers in human urine and plasma samples. This flexible strategy proved to be a useful tool to solve the problems of overlapped peaks and uncalibrated interferences encountered in quantitative LC-MS, and made the multi-targeted interference-free qualitative and quantitative analysis of β-blockers in complex matrices possible.

Screening of high α-arbutin producing strains and production of α-arbutin by fermentation.

A mutant Xanthomonas maltophilia BT-112 with high α-anomer-selective glycosylation activity was screened by a series of mutation methods including UV light, N-methyl-N-nitro-N-nitroso-guanidine treatment and quick neutron mutation. The α-arbutin titer increased 15-folds compared with the parent strain. The optimal conditions for culture medium and the operational conditions for lab-scale fermenter were investigated.

An alternative quadrilinear decomposition algorithm for four-way calibration with application to analysis of four-way fluorescence excitation-emission-pH data array.

A novel quadrilinear decomposition algorithm for four-way calibration (third-order tensor calibration), which was called as regularized self-weighted alternating quadrilinear decomposition (RSWAQLD), has been developed in this work. It originates from the alternating trilinear decomposition (ATLD) algorithm, inherits the philosophy behind self-weighting operation from the self-weighted alternating trilinear decomposition (SWATLD) algorithm. The RSWAQLD algorithm is based on a nearby least-squares scheme, in which two extra terms are added to each loss function, making it more stable and flexible.

[Epitopic multiple antigen peptide from α-fetoprotein elicit antitumor immune response in vitro and ex vivo].

Objective: To explore the antitumor effects of multiple antigen peptide (MAP) vaccine from α-fetoprotein (AFP) through AFP-specific cytotoxic T lymphocyte (CTL) against hepatoma in vitro and ex vivo.

Methods: Dendritic cells (DC) were generated from human peripheral blood mononuclear cells (PBMC) and HLA-A2.1-transgenic murine bone marrow.

Epidemiologic survey on hospitalized neonates in China.

Objective: To carry out a nationwide epidemiologic survey on the neonates in urban hospitals with an attempt to understand the disease spectrum and treatment outcomes of hospitalized neonates in China.

Methods: The clinical data of 43,289 hospitalized neonates from 86 hospitals in 47 Chinese cities (22 provinces) between January 1, 2005 and December 31, 2005 were retrospectively analyzed.

Results: The male:female ratio was 1.

The maintenance of the second-order advantage: second-order calibration of excitation-emission matrix fluorescence for quantitative analysis of herbicide napropamide in various environmental samples.

A rapid non-separative spectrofluorometric method based on the second-order calibration of excitation-emission matrix (EEM) fluorescence was proposed for the determination of napropamide (NAP) in soil, river sediment, and wastewater as well as river water samples. With 0.10 mol L(-1) sodium citrate-hydrochloric acid (HCl) buffer solution of pH 2.

Interference-free determination of and in plant samples using excitation-emission matrix fluorescence based on oxidationderivatization coupled with second-order calibration methods.

A sensitive excitation-emission fluorescence method with a second-order calibration strategy is proposed to simultaneously determine abscisic acid (ABA) and gibberellin (GA) contents in extracts of leaves and buds of ginkgo. The methodology is based on the alternating normalization-weighed error (ANWE) and the parallel factor analysis (PARAFAC) algorithms, which make it possible that the ABA and GA concentration can be attained in extract of plants even in the presence of unknown interference from potential interfering matrix contaminants introduced during the simple pretreatment procedure. Satisfactory recoveries were obtained although the excitation and emission profiles of the analytes were heavily overlapped with each other and the background in the extracts.

Seasonal variation of nitrogen-concentration in the surface water and its relationship with land use in a catchment of northern China.

Surface waters can be contaminated by human activities in two ways: (1) by point sources, such as sewage treatment discharge and storm-water runoff; and (2) by non-point sources, such as runoff from urban and agricultural areas. With point-source pollution effectively controlled, non-point source pollution has become the most important environmental concern in the world. The formation of non-point source pollution is related to both the sources such as soil nutrient, the amount of fertilizer and pesticide applied, the amount of refuse, and the spatial complex combination of land uses within a heterogeneous landscape.