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Biomedical subjects

C H Fan

Publications and source records attributed to C H Fan.

5 recordsLinked to original sources
PubMed2006

Nanocrystalline silicon-based oligonucleotide chips.

A novel oligonucleotide array sensor has been developed with nanocrystalline Si (ncSi) substrates. The ncSi was prepared by electrochemical etching technique. Our study indicated that both the binding capacity and the hybridization efficiency are dependent upon the particle size of ncSi. In contrary, the chips developed with Si substrates exhibit the lower binding capacity and hybridization efficiency. The improved performances of the sensor chips are attributed to the large specific surface area of ncSi compared to the existing conventional techniques. The sensor chips with the ncSi substrate of 13 nm-sized particle can be regenerated and reused for at least 12 times. The oligonucleotide array sensor also shows high stability, which can bear relatively the stringent conditions (e.g. 80 degrees C, 75% of relative humidity and 3.6 klx of irradiation).

Nanoparticles↗
PubMed2002

Photo-induced cytotoxicity of malonic acid [C(60)]fullerene derivatives and its mechanism.

The biological activities of fullerenes have attracted extensive attention in recent years. The aim of this paper is to study the relation of the photo-induced cytotoxicity of fullerene derivatives to their chemical structures as well as the possible cellular mechanism involved in the photocytotoxicity. Three C(60) derivatives with two to four malonic acid groups (DMA C(60), TMA C(60) and QMA C(60)) were prepared and the cytotoxicity of these compounds against HeLa cells was determined by MTT. Cell cycle was measured by flow cytometry. The results showed that the cytotoxicity of the malonic acid C(60) derivatives was irradiation- and dose-dependent. The sequence of their photo-induced growth inhibition was DMA C(60)>TMA C(60)>QMA C(60). Hydroxyl radical quencher mannitol (10mM) was not able to prevent cells from the damage induced by irradiated DMA C(60). DMA C(60), together with irradiation, was found to have an ability of inducing a decrease in the number of G(1) cells from 63 to 42% and a rise in that of G(2)+M cells from 6 to 26%. These data indicated that the number of malonic acid molecules added to C(60) played an important role in the phototoxicity, and the blockage of cell cycle might be a mechanism of this activity.

Carbon↗
PubMed1993

[Effect of covering the ground under canopy tree with straw on growth of dogwood (Cornus officinalis Sieb. et Zucc.)].

Experiments showed that the growth, blooming and bearing of dogwood (Cornus officinalis) were improved by covering the ground under canopy tree with straw. Growth of shoots, weight and thickness of 100 fresh leaves, and mineral nutrition of leaves were significantly higher than those of controls. Fruit buds of shoots, fruit setting per cluster, weight of 100 fresh fruits and yield per tree were increased by 17.9%, 20%, 31.7% and 33.5% respectively. Compared with uncovered trees, the blooming period of covered trees was delayed by 4-6 days.

Drugs, Chinese Herbal↗