Single-tube-genotyping of gastric cancer related SNPs by directly using whole blood and paper-dried blood as starting materials

AIM: To demonstrate an inexpensive method for typing gastric cancer related single nucleotide polymorphisms (SNPs) using whole blood or paper-dried blood as starting materials. METHODS: PCR amplification is directly carried out from the whole blood or paper-dried blood sample without any DNA extraction step. Before PCR, a blood sample, four primers, and all of biological reagents necessary for PCR were added at a time; After PCR, the amplified products were directly separated by slab gel electrophoresis or microchip CE without any purification. SNP typing was performed by tetra-primer PCR with two inner primers specific to each allele and two outer primers defining the length of allele-specific amplicons. Genotypes were directly discriminated by the size of amplicons specific to each allele, thereby avoiding any post-PCR process. RESULTS: Using a special PCR buffer, inhibitory substances in blood (including the anticoagulant in blood) and filter paper were effectively suppressed; a 'true' single-tube-genotyping is thus realized. We successfully determined genotypes IL-1B-511 and IL-1B-31 polymorphisms at the gene IL-1B by using whole-blood and paper-dried blood samples as starting materials respectively. The method is so sensitive that 0.5-1.0μL of blood sample is enough to give a satisfactory typing results. The genotyping results were confirmed by RFLP-PCR using purified genome DNA, indicating that amplification specificity was not affected by inhibitory components (including coagulants) in blood or filter paper. CONCLUSION: Compared with SNP typing methods based on purified DNA, the proposed method is labor saving, simple, inexpensive, and less cross-contaminated. It is promising to use this method to type other SNPs.

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST)

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST, also called the Guo Shou Jing Telescope) is a special reflecting Schmidt telescope. LAMOST’s special design allows both a large aperture (effective aperture of 3.6 m–4.9 m) and a wide field of view (FOV) (5°). It has an innovative active reflecting Schmidt configuration which continuously changes the mirror’s surface that adjusts during the observation process and combines thin deformable mirror active optics with segmented active optics. Its primary mirror (6.67m×6.05 m) and active Schmidt mirror (5.74m×4.40 m) are both segmented, and composed of 37 and 24 hexagonal sub-mirrors respectively. By using a parallel controllable fiber positioning technique, the focal surface of 1.75 m in diameter can accommodate 4000 optical fibers. Also, LAMOST has 16 spectrographs with 32 CCD cameras. LAMOST will be the telescope with the highest rate of spectral acquisition. As a national large scientific project, the LAMOST project was formally proposed in 1996, and approved by the Chinese government in 1997. The construction started in 2001, was completed in 2008 and passed the official acceptance in June 2009. The LAMOST pilot survey was started in October 2011 and the spectroscopic survey will launch in September 2012. Up to now, LAMOST has released more than 480 000 spectra of objects. LAMOST will make an important contribution to the study of the large-scale structure of the Universe, structure and evolution of the Galaxy, and cross-identification of multiwaveband properties in celestial objects.

Panel positioning error and support mechanism for a 30-m THz radio telescope

A 30-m TeraHertz（THz） radio telescope is proposed to operate at 200 μm with an active primary surface.This paper presents sensitivity analysis of active surface panel positioning errors with optical performance in terms of the Strehl ratio.Based on Ruze＇s surface error theory and using a Monte Carlo simulation,the effects of six rigid panel positioning errors,such as piston,tip,tilt,radial,azimuthal and twist displacements,were directly derived.The optical performance of the telescope was then evaluated using the standard Strehl ratio.We graphically illustrated the various panel error effects by presenting simulations of complete ensembles of full reflector surface errors for the six different rigid panel positioning errors.Study of the panel error sensitivity analysis revealed that the piston error and tilt/tip errors are dominant while the other rigid errors are much less important.Furthermore,as indicated by the results,we conceived of an alternative Master-Slave Concept-based（MSC-based） active surface by implementating a special Series-Parallel Concept-based（SPC-based） hexapod as the active panel support mechanism.A new 30-m active reflector based on the two concepts was demonstrated to achieve correction for all the six rigid panel positioning errors in an economically feasible way.

An active reflector antenna using a laser angle metrology system

An active reflector is one of the key technologies for constructing large telescopes, especially for millimeter/sub-millimeter radio telescopes. This article in- troduces a new efficient laser angle metrology system for an active reflector antenna on large radio telescopes. Our experiments concentrate on developing an active reflec- tor for improving the detection precisions and the maintenance of the surface shape in real time on the 65-meter prototype radio telescope constructed by Nanjing Institute of Astronomical Optics and Technology （NIAOT; http：//65rn.shao.cas.cn/）. The test results indicate that the accuracy of the surface shape segmentation and maintenance has the dimensions of microns, and the time-response can be on the order of minutes. Our efforts proved to be workable for sub-millimeter radio telescopes.

An Alternative Low-Cost Strategy for Simultaneous Sensitive Detection of Adjacent ESR1 Mutations in Single Circulating Tumor Cell

ESR1 mutation is of great clinical significance and being promoted as a marker of resistance to endocrine therapy in breast cancers.However,it is a challenging task to detect ESR1 mutations from traditional biopsies and cell-free DNA(cfDNA),especially for polyclonal mutations.This is mainly attributed to massive wild-type background and the low-abundance of the mutations.Here,using one-step single-cell amplification coupling with pyrosequencing,we developed and validated an original strategy for simultaneous sensitive detection of adjacent ESR1 mutations in single circulating tumor cell(CTC)from breast cancers.Unlike expensive single-cell sequencing used in previous studies,the strategy does not require complicated two-step amplification or high-cost single-cell amplification kits.Three pivotal parts involved in the strategy are collection of CTCs from whole blood of breast cancer patients,one-step single-cell amplification and pyrosequencing of single-cell amplicons.To achieve better e fficiency of one-step single-cell amplification for pyrosequencing,a set of experimental conditions were thoroughly trialed.The developed strategy enabled a highly specific detection of the ESR1 hotspot mutations from large wild-type background with the specificity as low as 1%and a high sensitivity of two copies of artificial samples or single-cell level and pretty good quantitative accuracy(R^(2)≥0.9888).Using this strategy,141 single CTCs from 11 cases of breast cancer patients were identified and collected,126 of which were successfully analyzed with a high rate of 89.4%.These results indicate that the cost-effective and reliable strategy could be used for clinical management,showing promising application in the treatment decision-making of breast cancer patients.

ZM1 magnesium alloy reinforced by carbon nanotubes using an improved casting process

Melt processing is a promising process to fabricate Mg-CNTs(carbon nanotubes)composites with high performance and large dimensions.In this work,the liquidmixing technique and ball-milling processes as well as the stirring casting method were used to prepare ZM1-1.0 CNTs-L and ZM1-1.0 CNTs-B composites,respectively.The composites were studied using optical microscopy(OM),Raman spectroscopy,scanning electron microscope(SEM),transmission electron microscope(TEM)and room-temperature tensile test.The results show that the yield strength(YS),ultimate tensile strength(UTS),elongation and microhardness values of the ZM1-1.OCNTs-L composite are improved by 37.3%,29.6%,37.0%and33.3%,respectively,compared with those of ZM1 alloy.The uniform dispersion of CNTs as well as the strong interfacial bonds with the Mg matrix is the main reason for the significant improvement in mechanical properties of the as-cast composite.Liquid mixing combined with the stirring casting method is favorable to fabricate Mg-CNTs composite with high mechanical properties.