Palladium-catalyzed disilylation of -halophenylethylenes enabled by 2-pyridone ligand.

A palladium-catalyzed disilylation reaction applicable for a variety of non-, α-, or β-substituted and α,β-disubstituted -halophenylethylenes has been developed. This reaction proceeds with high yields and very low catalyst loadings. The two C-Si bonds of the disilylated products could be well-differentiated chemoselectively in the reaction with various electrophiles.

Phosphorylation of C(sp)-H Bonds via 1,4-Palladium Migration.

1,4-Palladium migration has emerged as a reliable method for directed C-H functionalization. In contrast to coupling with carbon nucleophiles, limited examples with heteroatom nucleophiles have been reported. Herein we report a palladium-catalyzed intermolecular C(sp)-H phosphorylation reaction via 1,4-palladium migration, which is often difficult because of the strong coordination of phosphorus reagents to palladium catalysts.

Palladium-catalyzed cross-coupling of unreactive C(sp)-H bonds with azole C(sp)-H bonds by using bromide as a traceless directing group.

A palladium-catalyzed intermolecular cross-coupling of unreactive C(sp)-H bonds and azole C(sp)-H bonds with bromide as a traceless directing group is described. The judicious selection of the bulky and electron-rich phosphine ligand is the key for the success of this cascade process. The protocol features a broad substrate scope, excellent regioselectivity, and good functional group tolerance.

BacteriaAnchoring Hybrid Liposome Capable of Absorbing Multiple Toxins for Antivirulence Therapy of Infection.

Antivirulence therapy by cell membrane coated nanoparticles has shown promise against bacterial infections. However, current approaches remain unsatisfactory when facing () infections, since the secretes multiple bacterial toxins including endotoxins and exotoxins that are challenging to eliminate simultaneously. What is worse, the absorptive scavengers normally rely on random contact of the diffuse toxins, which is not efficient.

Silver-promoted synthesis of vinyl sulfones from vinyl bromides and sulfonyl hydrazides in water.

The synthesis of vinyl sulfones via silver-promoted cross-coupling of vinyl bromides with sulfonyl hydrazides was realized. Water was used as the sole solvent. Multisubstituted vinyl sulfones were easily prepared with excellent alkyl group tolerance.

Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors.

Seed germination is the key step for successful establishment, growth and further expansion of population especially for alien plants with annual life cycle. Traits like better adaptability and germination response were thought to be associated with plant invasion. However, there are not enough empirical studies correlating adaptation to environmental factors with germination response of alien invasive plants.

An asymmetric approach to bicyclo[2.2.1]heptane-1-carboxylates via a formal [4 + 2] cycloaddition reaction enabled by organocatalysis.

An organocatalytic formal [4 + 2] cycloaddition reaction has been realized that permits rapid access to a wide range of bicyclo[2.2.1]heptane-1-carboxylates in a highly enantioselective manner from simple starting materials under mild and operationally simple conditions.

Divergent total synthesis of the Lycopodium alkaloids huperzine A, huperzine B, and huperzine U.

Huperzine A, huperzine B, and huperzine U are congeners isolated from the Chinese herb Huperzia serrata (= Lycopodium serratum ) in minuscule amounts. The most efficient total synthesis of huperzine A, the first asymmetric total syntheses of huperzine B, and the first total synthesis of huperzine U have been achieved efficiently in overall yields of 17%, 10%, and 9%, respectively, each spanning 10-13 steps from (R)-pulegone. The featured steps include palladium-catalyzed Buchwald-Hartwig coupling and Heck cyclization reactions and an Ir-catalyzed olefin isomerization reaction.

[Study on uniformity of optical field in static Fourier transform spectrometer].

Since the Fourier transform spectrometer based on multi-micro mirrors samples the interferogram image which corresponds to each OPD in the transverse optical field, the spatial distribution of the irradiance has much effect on the quality of the interferogram. In the present paper, distribution function is introduced in this spectrometer system. By means of simulation, the contrast of the interferogram modulated by distribution function is depressed in the fringe area and the concomitant line appears in the spectrum.

[Analysis of collimation error in Fourier transform infrared spectrometer based on step mirrors].

The collimation error in Fourier transform spectrometer has many effects on the interferogram and the spectrogram. By means of modulation, the authors found the reverse of contrast in the interferogram and the side slope noise in the spectrogram due to the collimation error. The authors analyzed the signal-to-noise ratio and resolution at different factor of beam divergence.

Construction of highly functional quaternary carbon stereocenters via an organocatalytic tandem cyanation-allylic alkylation reaction.

The first tertiary amine-catalyzed tandem cyanation-allyic alkylation (CAA) reaction of aldehydes, appropriate cyanide sources, and Morita-Baylis-Hillman (MBH) adducts has been developed, which provides a facile access to densely functionalized products containing O-substituted quaternary centers.

Further evaluation of the characteristics of Treponema pallidum-specific IgM antibody in syphilis serofast reaction patients.

Syphilis serofast reaction (SSR) is common in clinical work. From June 2005 to May 2009, 1208 syphilis patients were chosen for research by the Xiamen Center of Clinical Laboratory in China. Serologic tests were performed with toluidine red unheated serum test (TRUST) and Treponema pallidum particle agglutination (TPPA).

[Influence of extended light source on spectral reconstruction in a micro FTIR].

The influence of extended light source on spectral reconstruction in the FTIR (fourier transform infrared spectrometer) based on step mirrors was discussed in the present paper. The relationship between coherent intensity and solid angle was calculated. It was found that the coherent length became shorter and the spectrum resolving power became lower as a result of solid angle produced by the extended light source.

Expression of inflammatory and apoptosis factors following coronary stent implantation in coronary heart disease patients.

We investigated the changes in characteristics of neutrophil CD11b, monocyte CD11b, platelet CD62P, endothelin (ET), and neutrophil CD178 in patients with coronary heart disease (CHD) before and after primary coronary stenting. A total of 41 patients with CHD who underwent coronary stenting and 40 control subjects were enrolled in the study. In CHD patients, peripheral blood samples were taken 24 h before and 30 min, 24 h, and 72 h after successful coronary stenting.

[Analysis of diffraction in Fourier-transform infrared spectrometer based on step mirrors].

Diffraction in the Fourier-transform infrared spectrometer based on step mirrors was analyzed in the present paper, and the influence of diffraction on the spectrum reconstruction with different width of step mirrors, wavelengths and distance was also discussed. It is shown that the influence of diffraction is low when the distance is less than 10 cm and the width of mirror is more than 0.5 mm.

[Development and application of geographic information system of Aedes vector in Chaozhou city, Guangdong province].

Objective: To explore the spatial distribution character of dengue fever and the change of Aedes' population, so as to provide macroscopical decision-making evidences of prevention and supervision on dengue fever.

Methods: (1) Collecting data on morbidity of dengue and supervision on vector's population in the corresponding period. (2) Drawing digitized map of Chaozhou in scale of 1:50,000, including elements of boundary, residential areas, road and traffic, altitude, water systems etc.