Constant Stress Accelerated Life Tests for Vacuum Fluorescent Display Based on Least Square Method

To estimate the life of vacuum fluorescent display （VFD） more accurately and reduce test time and cost, four constant stress accelerated life tests （CSALTs） were conducted on an accelerated life test model. In the model, statistical analysis of test data is achieved by applying lognormal function to describe the life distribution, and least square method （LSM） to calculate the mean value and the standard deviation of logarithm. As a result, the accelerated life equation was obtained, and then a self-developed software was developed to predict the VFD life. The data analysis results demonstrate that the VFD life submits to lognormal distribution, that the accelerated model meets the linear Arrhenius equation, and that the precise accelerated parameter makes it possible to acquire the life information of VFD within one month.

Constant-Step Stress Accelerated Life Test of VFD under Logarithmic Normal Distribution Case

In order to solve the life problem of vacuum fluorescent display (VFD) within shorter time, and reduce the life prediction cost, a constant-step stress accelerated life test was performed with its cathode temperature increased. Statistical analysis was done by applying logarithmic normal distribution for describing the life, and least square method (LSM) for estimating logarithmic normal parameters. Self-designed special software was used to predict the VFD life. It is verified by numerical results that the VFD life follows logarithmic normal distribution, and that the life-stress relationship satisfies linear Arrhenius equation completely. The accurate calculation of the key parameters enables the rapid estimation of VFD life.

CLONING AND IDENTIFICATION OF A GENE RELATED TO THE DIFFERENTIATION OF HUMAN GASTRIC ADENOCARCINOMA CELLS

Objective: To compare the differential expression of mRNA between MKN-28 (highly differentiated) and MKN-45 (poorly differentiated) gastric adenocarcinoma cells and identify genes involved in human gastric adenocarcinoma differentiation. Methods: Differential expression of mRNA between MKN-28 and MKN-45 adenocarcinoma cells was investigated by fluorescent differential display (FDD). Differentially expressed cDNA was analyzed by bioinformatics and confirmed by RT-PCR and Northern-blot. Results: 45 differential fragments were finally attained. One of them (No. 10) was an approximate 750 bp cDNA and highly up-regulated in MKN-45 cells as compared with MKN-28 cells. By using Blastn and UniGene database analysis, we found the fragment was mapped to chromosome 14q11.2–q12 and showed a significant homology to Bcl-2 binding protein gene (BNip3), which was recently identified encoding pro-apoptosis protein located in mitochondrial. Conclusion: The BNip3 induced apoptosis could be suppressed by interacting with bcl-2. The BNip3 gene in tumor cells might be up-regulated by the hypoxia response element through the HIF1a transcription factor, causing death of the hypoxic cells at the center of the tumor where vascularization is usually poor in the process of tumor development.

A Rice CaMBP Gene is Induced in Organ-Specific Manner by Both Chilling and Heat-Shock Treatments

A rice CaMBP gene, OsCaMBP （AB363406）, was isolated from a chilling treated rice using the fluorescent differential display （FDD） screening method. Its cDNA sequence （2094 bp） contains an opening reading frame （ORF） encoding a 569 amino acids protein （63.2 kD）. OsCaMBP has the typical structural features of the CaMBP family, including the conserved IQ calmodulin-binding motif at the N-terminus. Homology analysis revealed 38.25%-47.28% identities of OsCaMBP with other CaMBPs in plants. RT-PCR analysis showed that the expression of OsCaMBP was remarkably inducible under the chilling （8℃） and heat-shock （42℃） treatments. OsCaMBP was undetectable under the normal conditions, and induced under the chilling treatment for 1 h, as well as the heat-shock treatment for 15 min, suggesting that the gene plays important roles in the signaling pathway in rice under both chilling and heat-shock stresses.

Differential Display of Cotton cDNAs Expressed by Salicylic Acid Induction

Salicylic acid (SA) is very important in systemic acquired resistance and hypersensitive response in plant defense, and yet its role is not fully understood. This study seeks to clarify the mechanism of SA induced resistance in cotton. Total RNA was extracted from low gossypol cultivated cotton seedlings treated with exogenous SA and subjected to fluorescent differential display PCR (FDD PCR). Seven cDNA fragments were selected from the total ten differential bands. Comparison with Genbank database shows that all seven cDNA sequences are newly discovered in cotton. However, they share high amino acid identity to some registered cDNAs. Among them, three of the cDNAs could be predicted to encode basic chitinase, penicillin binding 6 b precursor and ATP dependent DNA helicase RecG, while the functions of the other four cDNAs are undetermined. Dot blot analysis demonstrates that the expression of five cDNAs in cotton seedlings is induced by SA, while SA induction has a negative effect on the transcript accumulation of the other two cDNAs (E13 and E14). Since SA was previously shown to enhance the resistance to cotton wilt disease, the finding of a basic chitinase gene in cotton expressed by SA induction will provide a new insight into induced disease resistance in cotton.