Cobalt-Catalyzed Reductive Cross-Coupling To Construct Csp3-Csp3 Bonds via Csp3-S and Csp3-X Bonds Activation.

A cross-electrophilic coupling of benzyl sulfonium salts with alkyl halides forming Csp3-Csp3 bonds is described by using a Co-based catalytic system. The activation of the stable Csp3-S bond of benzyl sulfonium salts under mild reaction conditions leads to various functionalized alkyl derivatives. Preliminary mechanistic studies suggest the involvement of alkyl radicals formed from both alkyl halides and benzyl sulfoniums through a single electron transfer.

Structure-Dependent Optical Properties of Self-Organized Bi2Se3 Nanostructures: From Nanocrystals to Nanoflakes.

Bismuth selenide (Bi2Se3), with a wide bulk band gap and single massless Dirac cone at the surface, is a promising three-dimensional topological insulator. Bi2Se3 possesses gapless surface states and an insulator-like bulk band gap as a new type of quantum matter. Different Bi2Se3 nanostructures were prepared using electron beam evaporation with high production efficiency. Structural investigations by energy-dispersive X-ray analysis, scanning electron microscopy, and X-ray diffraction revealed the sample stoichiometries and the structural transition mechanism from nanocrystals to nanoflakes. The optical properties systematically probed and analyzed by spectroscopic ellipsometry showed strong dependence on the nanostructures and were also predicted to have structure-modifiable technological prospects. The optical parameters, plasma frequencies, scattering rates of the free electrons, and optical band gaps were related to the topological properties of the Bi2Se3 nanostructures via light-matter interactions, offering new opportunities and approaches for studies on topological insulators and spintronics. The high-quality Bi2Se3 nanostructures provide advantages in exploring novel physics and exploiting prospective applications.

Berberine inhibits LPS-induced TF procoagulant activity and expression through NF-κB/p65, Akt and MAPK pathway in THP-1 cells.

BACKGROUND: Considering the key role of TF in coagulation of sepsis or acute lung injury (ALI), we investigated whether berberine (BBR) could inhibit TF expression and procoagulant activity and explored its possible mechanism. METHODS: The effects of berberine on the expression, procoagulant activity of TF and related signal pathways induced by lipopolysaccharide (LPS) were observed in THP-1 cells. RESULTS: Our results showed that berberine could inhibit LPS-induced TF activity and expression, and down-regulate NF-κB, Akt and MAPK/JNK/p38/ERK pathways. CONCLUSION: Berberine inhibits TF expression and related pathway, which provides some new insights on its mechanism for sepsis treatment.