Method to Calculate the Retention Index in Hydrophilic Interaction Liquid Chromatography Using Normal Fatty Acid Derivatives as Calibrants.

Hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) is a complementary technique to reversed-phase liquid chromatography-mass spectrometry (RPLC-MS) and has been widely used to expand the coverage of the metabolome in MS-based metabolomics. However, the use of HILIC retention time (HILIC RT) in metabolites annotation is quite limited because of its poor reproducibility. Here, we developed a method to calculate the retention index in HILIC (HILIC RI) for calibration of HILIC RT. In this method, a mixture of 2-dimethylaminoethylamine (DMED)-labeled fatty acid standards with carbon chain length from C2 to C22 were selected as calibrants to establish a linear calibration equation between HILIC RT and carbon number for the calculation of HILIC RI. The calculated HILIC RIs based on a regression equation could efficiently calibrate the retention time shifts for 28 DMED-labeled carboxyl standards and DMED-labeled carboxyl metabolites in rat urine, serum and feces on a HILIC column with different gradient elution conditions. Furthermore, the developed HILIC RI strategy was applied to RT calibration of screened metabolites, the annotation of isomers in HILIC-MS-based metabolomics analysis for real samples, and the correction of isotope effects in chemical isotope labeling HILIC-MS analysis. Taken together, the resulting HILIC RI strategy is a promising analytical technique to improve the accuracy of metabolite annotation; it would be widely used in HILIC-MS-based metabolome analysis.

A hierarchical architecture S/MWCNT nanomicrosphere with large pores for lithium sulfur batteries.

A hierarchical S/MWCNT nanomicrosphere for lithium/sulfur batteries with a high power and energy density as well as an excellent cycle life is introduced. Sulfur was uniformly coated on the surface of functional MWCNTs, which serves as a carbon matrix, to form a typical nanoscale core-shell structure with a sulfur layer of thickness 10-20 nm. Then the nanoscale sulfur intermediate composite was ball-milled to form interwoven and porous sphere architecture with large pores (around 1 µm to 5 µm). Different from most sulfur/carbon materials with micropore and mesopore structure, the micrometre scale S/MWCNT nanomicrosphere with a large pore structure could also exhibit high sulfur utilization and cycle retention. It could maintain a reversible capacity of 1000 mA h g(-1) after 100 cycles at 0.3 A g(-1) current density. And it even remained 780 mA h g(-1) after 200 cycles at 0.5 A g(-1) and 650 mA h g(-1) after 200 cycles at 1 A g(-1), showing a significant cyclability enhancement. It is believed that under the collective effect of hierarchical architecture, as well as the existence of carboxyl functional groups, sulfur/carbon materials with large pores could also exhibit an excellent electrochemical performance. The synthesis process introduced here is simple and broadly applicable, which would not only be beneficial to design new materials for lithium sulfur batteries but can also be extended to many different electrode materials for lithium ion batteries.

7-(Hydroxy-meth-yl)-2-(1-hydr-oxy-1-methyl-ethyl)-4-meth-oxy-2,3-dihydro-5H-furo[3,2-g]chromen-5-one methanol hemisolvate.

The title compound (cimifugin), C(16)H(18)O(6)·0.5CH(3)OH, was isolated from the rhizome of Actaea asiatica Hara. The asymmetric unit contains two independent mol-ecules and a solvent methanol mol-ecule. The five-numbered ring adopts an envelope conformation in each molecule. Intra- and inter-molecular O-H⋯O hydrogen bonds stabilize the crystal structure.

[Study the effects of flavonoids of Rhizoma Drynariae on gene level of rats without ovaries by technology of cDNA array].

OBJECTIVE: To study the effects of flavonoids of Rhizoma Drynariae on gene level of rats without ovaries (OP) by technology of cDNA array. METHOD: The models of rats without ovaries were made After. 24 weeks of treatment, put them to death and sampled 6 ml blood from the abdominal aorta and 4cm spinal cord. Take out the total RNA, then separate the mRNA to check. RESULT: There is 70 genes difference between the blank control group and model group, 9 genes difference between the blank control group and flavonoids of Rhizoma Drynariae group. The genes over expression of OP rats models regain normal after the models were fed on flavonoids of Rhizoma Drynariae. There are no differences in the spinal cords genes in the cDNA array analysis of this trail. CONCLUSION: The genes over expression of OP rats models regain normal after the models were fed on flavonoids of Rhizoma Drynariae for 6 months. The result shows that the flavonoids of Rhizoma Drynariae does have certain effects on the gene expression of rats without ovaries.

A Novel Technique of Long-Segment Tracheal Repair With Extended Bronchial Flap of Right Upper and Main Bronchus Plus Tracheoplasty.

Long-segment tracheal resection and repair pose a great challenge. We present a successful case of long-segment tracheal defect repair with extended bronchial flap of the right upper and main bronchus, together with a tracheoplastic method. This is a novel technique for repairing a large tracheal defect with an extended pedicled bronchial flap in specific situations.