Search

In this study, isoegomaketone(IK) was isolated from Perilla frutescens(L.), a Chinese herbal. The effects of IK were examined by cell viability assay, colony formation assay, xenograft tumor assay and western blotting in HCC cells. We found that IK inhibited cell viability, and its administration decreased tumor volume and weight profoundly. The presence of IK(10 nmol/l) produced a dramatic decrease of pAkt, while total Akt level was not affected. The data suggested that IK from perilla suppressed HCC tumor growth via blocking PI3K/Akt signaling pathway.

Abstract oTo satisfy the requirement of large telescope, a large aperture focal plane shutte r with aperture size of 3 200mm was researched and designed to realize, which could be star ted and stopped in a relative short time with precise position, and also the blades could open and close at the same time at any orientation. Timing-belts and stepper motors were adopted as the drive mechanism. Velocity and position of the stepper motors were controlled by the PWM pulse generated by DSP. Exponential curve is applied to control the velocity of the stepper motors to make the shutter start and stop in a short time. The closing/open time of shutter is 0.2s, which meets the performance requirements of large telescope properly. Keywords olarge telescope; shutter; timing-belt, aperture size, closing/open time OMT12-OM100-18 1. INTRODUCTION With the requirement of a large telescope, a large aperture focal plane shutter which is mounted before the CCD is needed, while Camera exposure shutters with apertures in excess of 100 mm are hard to find on the ¯market °. Traditional shutters can be generally assorted to two categories by framework, lamina-type shutter and center-type shutter. The mechanism of lamina-type shutter is motor drive each lamina move by linkage mechanism, which is usually used in camera. The mechanism of center-type shutter is electromagnet control the movement of each blade by linkage mechanism ewhich is mostly used in telescope with small aperture. A ll kinds of shutters can't be simply enlarged with the similar framework. Shutter technology abroad leads us, their structure are complicated, and BONN shutter is famous among them, while the dimension can't satisfy our need. And most shutters abroad used in each large telescope are specifically designed according to different dimensional limitation and speed requirement. They are practically unavailable to our telescope. We have to design a shutter of the whole dimension less than 3 500mm and thinner than 20mm with aperture of 3 200mm, and the open/close time less than 0.2s.

A complementary DNA (cDNA) fragment library from SH-SY5Y cells is constructed using a restriction display polymerase chain reaction (RD-PCR) technique. Messenger RNA (mRNA) is extracted from SH-SY5Y cells and single-strand cDNA synthesised using an anchored oligo primer (dT18). The second strand is produced by nick translation. The double strands are cleaved with the restriction enzyme Sau3AI and the fragments ligated with universal linker. The products are amplified with universal primers and selected primers, ligated into the pMDI8-T vector, and then sequenced. The library constructed contained 136 subgroups, each comprising seven to 12 cDNA fragments. RD-PCR proved a simple, effective way to construct a cDNA library, and this will contribute to the investigation of gene expression in the neuron in future microarray studies.

The oncoprotein E6 of high-risk human papillomavirus (HPV) types promotes cell proliferation and contributes to carcinogenesis of HPV-positive cervical cancer cells. In this study, we used small interfering RNA (siRNA) technology to silence the E6 gene in HPV-18-transformed human cervical cell line HeLa and determined the effects of E6 gene knockdown on the cell by using microarray-based gene expression profiling coupled with gene functional classification with bioinformatics methods. Silencing RNA prepared by siRNA expression cassettes against HPV-18 E6 gene could significantly inhibit E6 gene expression and induce HeLa cells to apoptosis. The microarray analysis identified 359 differentially expressed genes containing 307 up-regulated and 52 down-regulated genes. We analyzed the gene functions and cellular pathways in detail, including cell cycle-related genes, CCNG1 and p21; apoptosis-related genes, CASP4, CASP6, IGFBP3, and DFFA; ubiquitin proteolysis pathway-related genes, UBE3A and UBE2C; keratinocyte differentiation-related genes, KRT4, KRT6E, and KRT18; and antioncogenes, RECK and VEL. In addition, it can be concluded that cellular apoptosis induced by HPV-18 E6 siRNA mainly depends on the P53 and ubiquitin proteolysis pathway to regulate gene expression, consequently inhibiting cell proliferation and promoting cell apoptosis. Meanwhile, activation of antioncogene and upper regulation of immunization-related genes signified the degression of the malignant extent of tumor cells after E6 inhibition. Our approach, which combines the use of siRNA-mediated gene silencing, microarray screening, and functional classification of differential genes, can be used in functional genomics study to elucidate the role of E6 oncogene in the carcinogenesis of HPV-18 and provide some possible targets for clinical treatment and drug development of cervical cancer.

Currently, screening for high-risk human papillomavirus (HPV) infection remains an important health concern throughout the world, because of the close association between certain types of HPV and cervical cancer. In this study, we explore the possibility of using approximately 70mer oligonucleotide microarray for detection and genotyping of HPV. The approximately 70mer type-specific oligonucleotide probes of four different types HPV were designed by using biological software Array designer 2.0, which analyzed the whole genome sequences of HPV and selected optimal probes. These probes were synthesized and printed onto the surface of glass slides in order to prepare a low-density microarray. HPV samples were labeled with fluorescence dyes Cy3 using a method of restriction display polymerase chain reaction (RD-PCR). HPV plasmid DNA was restricted with Sau3A I to produce multiple fragments that were ligated to adaptors subsequently and used as PCR template. PCR labeling was performed with the fluorescently labeled universal primer (Cy3-UP) whose sequence is designed according to the adaptor of the RD-PCR approaches. The labeled samples were hybridized with the oligonucleotide microarray. The scanning results showed that HPV DNA hybridized specifically with multiple spots correspondingly to show positive signals, whereas no signals were detected of all the negative and blank controls. These results demonstrated that approximately 70mer oligonucleotide microarray can be applied to HPV detection and genotyping. The application of RD-PCR in the sample labeling can increase significantly the sensitivity of the assay and will be especially useful for the discriminate diagnosis of multiple pathogens.

A new molecular-baiting method was studied by retrieving targeted gene fragments from an oligonucleotide microarray bait after hybridization. To make the microarray bait, 70-mer oligonucleotides that were designed to specifically represent the SSA1 gene of Saccharomyces cerevisiae were printed on the slide. Samples of the Saccharomyces cerevisiae mRNA were extracted and labeled by the RD-PCR (Restriction Display PCR) method using the Cy5-labelled universal primer, then applied for hybridization. The sample fragments that hybridized to the microarray were stripped, and the eluted cDNAs were retrieved and cloned into the pMD 18-T vector for transformation, plasmid preparation, and sequencing. BLAST searching of the GenBank database identified the retrieved fragments as being identical to the SSA1 gene (from 2057-2541bp). A new method is being established that can retrieve the sample fragments using an oligo-microarray-bait.

Vaccinia virus is a member of the orthopoxvirus group, to which also belongs variola virus, one of the most hazardous pathogens known to man. To establish a model system to detect orthopoxviruses, a vaccinia oligonucleotide microarray is designed, produced and tested. Vaccinia virus is used to test the prepared microarrays. The virus DNA samples in different propagation phases are extracted and hybridised with the oligonucleotide microarray. The results showed that the oligonucleotide microarray can detect vaccinia virus with high specificity and sensitivity.

This study explores the restriction display-polymerase chain reaction (RD-PCR) application of a new chip-based nucleic acid analysis system (Agilent 2100 bioanalyser) in a gene differential expression study. Total RNAs is extracted from Saccharomyces cerevisiae, double-stranded complementary DNA (cDNA) is synthesised by reverse transcription from the purified messenger RNA (mRNA), RD-PCR conducted to obtain the cDNA fragments and bioanalyser and agarose gel electrophoresis compared for the analysis of RD-PCR products. The bioanalyser proved to be faster and more sensitive in separating and detecting gene fragments, and was also able to compare different gene fragments quantitatively. Using this technology, comparison of several differential gene fragments is performed.

Cryogenic optical system undergoes wide temperature change; therefore it must be athermal. That means when the system is cooled down to very low temperature, its imaging property should be kept as good as at room temperature. One way to achieve athermal optical system requires that all optical and mechanical parts in the system be made from same material. An all-reflective cryogenic optical system was thus developed in IOECAS, in which aluminum alloy was utilized to make such a system. This paper describes the key techniques for manufacturing this cryogenic optical system: material selection, forging process of the aluminum alloy blanks, initial machining, heat treatments, and final figuring. The cryogenic test of the developed system proved the validity of the manufacturing process.

An all aluminum reflective optical system was tested to evaluate its optical performances at near liquid nitrogen temperature. A special cryogenic dewar was designed and fabricated with an optical window made of quartz glass on the front wall of the dewar. The optical system under test and a reference plane mirror, which were mounted into the dewar and cooled by liquid nitrogen, formed a double pass interferometric test schema together with a He-Ne interferometer of Fizeau type outside the dewar. The test results showed that there was little differences between the wavefront errors before and after the optical system is cooled, and in both cases the optical system had a diffraction limited imaging quality.