Improving the biotransformation of phytosterols to 9α-hydroxy-4-androstene-3,17-dione by deleting embC associated with the assembly of cell envelope in Mycobacterium neoaurum.

The conversion of low value-added phytosterols into 9α-hydroxy-4-androstene-3,17-dione (9-OHAD) by mycobacteria is an important step in the steroid pharmaceutical industry. However, the highly dense cell envelope with extremely low permeability largely affects the overall transformation efficiency. Here, we preliminarily located the key gene embC required for the synthesis of lipoarabinomannan from lipomannan in Mycobacterium neoaurum.

A simple liquid chromatography tandem mass spectrometric method for fast detection of hydrogen sulfide based on thiolysis of 7-nitro-2, 1, 3-benzoxadiazole ether.

The long identified toxic gas, hydrogen sulfide (HS), which has also been confirmed as the third gaseous signaling molecule following NO and CO, plays important roles in various physiological and pathological process. The current most established quantification method for HS is HPLC method coupled with fluorescence detection after derivatization with a costly fluorescent reagent, Monobromobimane (MBB). However, The MBB method is characterized by strict reaction condition, long reaction time, tedious operation, and inconsistent reported results.

New azaphilones, phomopsones A-C with biological activities from an endophytic fungus Phomopsis sp. CGMCC No.5416.

Three undescribed azaphilones, phomopsones A-C (1-3) and two known azaphilones (4-5) were isolated from the culture of endophytic fungus Phomopsis sp. CGMCC No.5416 from the stems of Achyranthes bidentata.

Influence of heat treatments upon the mechanical properties and in vitro bioactivity of ZrO2-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics.

Zirconia-toughened MgO-CaO-SiO2-P2O5-CaF2 glass-ceramics are prepared using sintering techniques, and a series of heat treatment procedures are designed to obtain a glass-ceramic with improved properties. The crystallization behavior, phase composition, and morphology of the glass-ceramics are characterized. The bending strength, elastic modulus, fracture toughness, and microhardness of the glass-ceramics are investigated, and the effect mechanism of heat treatments upon the mechanical properties is discussed.

[Studies on properties of aggregates and Langmuir-Blodgett films for centrosymmetric naphthalocyanine molecules].

Deposition of Langmuir-Blodgett films and the aggregative properties of three centrosymmetric naphthalocyanine derivatives were investigated by using linear absorption spectra. Good LB films could be formed for all the three compounds. In dilute solution,the monomers are the main formation for the tetra-tert-butyl-cyan naphthalocyanine.