Search

Selecting stably expressed reference genes is crucial for evaluating real-time quantitative polymerase chain reaction (RT-qPCR) data via the relative quantification method. In the present-day study, our aim was to select optimal reference genes (RGs) for the investigation of target gene (TG) expression profiling in cancerous human laryngeal and hypopharyngeal tissues.12 cancerous laryngeal tissues and 10 cancerous hypopharyngeal tissues were investigated. The expression characteristics of 11 reference genes (18S rRNA, GAPDH, B2M, ACTB, TBP, ALAS1, RPL29, HMBS, HPRT1, GUSB, and PUM1), which were commonly used in RT-qPCR for the analysis of gene expression, were investigated using the geNorm, NormFinder, and BestKeeper algorithm programs.HMBS, ALAS1, and B2M were suggested as optimal RGs for studying human laryngeal and hypopharyngeal cancerous tissues together, laryngeal cancerous tissue by itself, and hypopharyngeal cancerous tissue by itself, respectively. If 2 or more reference genes are needed to achieve better standardization, 3 reference genes can optimally be used in combination to improve the accuracy of relative quantitation normalization. The recommended combinations for studying human laryngeal and hypopharyngeal cancerous tissues together, laryngeal cancerous tissue by itself, and hypopharyngeal cancerous tissue by itself were HMBS + HPRT1 + GUSB, ALAS1 + GUSB + HMBS, and B2M + HPRT1 + TBP, respectively.The recommended reference genes could be used to improve the accuracy of gene expression studies on the molecular mechanisms of cancerous human laryngeal and hypopharyngeal tissues. The selected combination of reference genes can effectively improve the accuracy of the relative quantitative diagnosis of gene expression levels, such as messenger RNA, circular RNA, and long-noncoding RNA.

Aerosol samples were collected in Beijing-Tianjin (developedregion); Lushan Mt. and Flower Mt. (clean region); Namjiagbarwa Peak (Tibet) and Zhangjiajie(nature region). Aerosol samples were analyzed for chemical composition study using XRF, PIXE, IC and TEGA, data processed with enrichment factor analysis. Results show that aerosols in the three regions are specific by their own chemical composition.

A new analytical method for the separation and determination of seven aqueous depsides in salvia miltiorrhiza by HPTLC has been developed. The seven depsides are protocatechualdehyde, caffeic acid, methyl rosmarinate, rosmarinic acid, salvianolic acid A, B and C. Using chloroform-ethyl acetate-benzene-formic acid(2.4:2:1:0.6) as developing solvent A, protocatechualdehyde was separated; using chloroform-ethyl acetate-benzene-formic acid-methanol (1.5:2:1:1:0.1) as developing solvent B, the other six constituents were well separated. The aqueous depsides were detected at the wave lengths of lambda S = 300 nm and lambda R = 240. This method is simple, rapid, sensitive and accurate. The contents of seven depsides in several Salvia species were determined.

A new component, gnetifolin A, was isolated from the ethyl acetate fraction of the stem of Gnetum parvifolium (Warb.) C.Y. Cheng together with three known components isorhapontigenin, resveratrol and beta-sitosterol. The structure of gnetifolin A has been established as 2-(3',5'-dihydroxy-4'-methoxyphenyl)-3-methoxy-5-hydroxybenzofuran by spectroscopic methods (UV, IR, MS, 1HNMR, 13CNMR, 2D-NMR).

In containing our studies on the flavonoids from Scutellaria amoena C.H. Wright, a new flavanone (I) and six known compounds (II-VII) were isolated from the roots of this plant. On the basis of spectroscopic analysis (UV, 1H NMR, 13C NMR, MS and CD) and chemical evidence, the structure of the new compound was elucidated as (2S) -2',5,6'-trihydroxy-7-methoxyflavanone (I) and named scuteamoenin, the other six known compounds were identified as (2R,3R) -3,5,7-trihydroxyflavanone (II), 2',3,5,6,7-pentahydroxyflavone (III), 2',5,7-trihydroxy-6-methoxyflavone (IV), skullcaflavone II (V), chrysin (VI) and beta-sitosterol (VII) respectively. Compounds II-VII were obtained from this plant for the first time.

A method of TLC densitometry was developed to determine the active ingredients (Wuweizisu A, B, C; Wuweizichun A, B; Wuweizi ester and schisanhenol) in Schisandra kernels. The samples were extracted with hexane (3 X 5 ml) for 8, 4 and 4 h respectively. The hexane extract was evaporated to dryness and then dissolved in 1 ml of methanol. Standard solutions and sample solutions were spotted on a silica gel GF254 plate, and developed with toluene-ethyl acetate (9:1) for 18 cm (for Wuweizisu A, B, C) and with toluene-ethyl acetate (4:6) for 18 cm (for Wuweizichun A, B, Wuweizi ester and schisanhenol). On examining the chromatogram under UV light the ingredients appeared as dark spots. A Shimadzu TLC model 910 was used for scanning at lambda s 260 nm and lambda R 350 nm by reflection mode. Linear calibration curves were obtained for the 7 constituents in the range of 1-5 micrograms. The average recoveries of the 7 constituents were 92.4-101.6%; the variation coefficients were 1.62-5.28%. The spots were stable for more than 24 h. This method is sufficiently simple, rapid and accurate for routine analysis.

This paper presents results from a study of soot pollution problems in the Beijing-Tianjin area of China in 1983–1984. Soot is one of the main air pollutants in northern China. The average particular carbon concentration in the air is about 30 μg m−3 and the source is mainly coal combustion. Based on these experiments, using the moving parcel method, we estimate the conversion rate for oxidation of SO2 to sulfate to be in the range 2.2%–5.7% h−1. Contributions of the different components of the aerosol to visibility reduction have been calculated. The apparent sulfate and soot contributions to the visibility decrease are 52%–58% and 22%–29%, respectively. Results of a laboratory study indicate that transition metal ions and soot can be important catalysts for the oxidation of S(IV) in aqueous solution. Under ultraviolet light, transition metal catalysis is faster, while absence of such light favors catalysis by soot. Thus soot can negatively affect visibility both directly, by light absorption and scatter...

The lignans contained in the fruits of Schisandra chinensis and S. sphenanthern were determined by HPLC. Their chromatograms are different. 7 samples of S. chinensis from 6 habitats contain the same lignans, but in different quantity, while 16 samples of S. sphensnthern contain lignans different both in quality and quantity.

Data from a survey of the drug market and investigation of the original plant of "Tu-hou-po", after careful botanical examinations, showed that the drugs were derived from 5 species of the genus Manglietia of Magnoliaceae, viz. Manglietia chingii Dandy, M. insignis (Wall.) Bl., M. duclouxii Finet et Gagnep., M. yuyuanensis Law and M. szechuanica Hu. Comparisons of the main characteristics of the plants, Tu-hou-po and Hou-po crude drugs and chemical components showed that Manglietia is taxonomically the closest to Magnolia and contained similar components (tab 1-2 and fig 1). The results of HPLC analysis demonstrated that they contained magnolol, honokiol, magnocurine and salicifoline, in different quantities. However, no magnosprengerine was detected. Besides, it was also found that the percentage of magnolol and honokiol contents were higher, while that of magnocurine was lower in Hou-po. On the contrary, the content of magnocurine was higher, while that of magnolol and honokiol were lower in Tu-hou-po. Manglietia chingii (Tu-hou-po) is being used as the Chinese traditional drug "Hou-po" in the clinic in Guangxi. Therefore, M. chingii is noteworthily exploited as a new resource of Hou-po for further research.