二维混合MIMO相控阵雷达的嵌套阵列结构设计

针对二维混合多输入多输出(multiple input multiple output,MIMO)相控阵雷达发射阵列子阵分割带来的自由度(degree of freedom,DOF)减小问题,提出了基于嵌套阵结构的收发阵列设计方法。首先给出基于一维嵌套阵的二维混合MIMO相控阵雷达发射阵列,在此基础上将接收端设置为嵌套阵,最后通过做虚拟阵列以及差异阵列,形成虚拟阵元数目扩展,在保留混合MIMO相控阵雷达优势的基础上增大了阵列DOF。同时给出了阵列流形的闭合表达式,推导出了基于最大DOF准则的最优嵌套阵元数目。仿真实验表明,相较于传统和互质的混合MIMO相控阵雷达,所提方法可有效提高阵列DOF和波达方向估计精度。

基于L形嵌套的混合MIMO相控阵雷达阵列设计

混合MIMO相控阵雷达发射端的子阵分割会导致自由度损失,为了解决这一问题,提出了一种基于嵌套阵结构的L形收发阵列设计方法。首先将发射端的混合MIMO相控阵雷达线阵纵向放置,然后接收阵列设计为横向布置的嵌套阵结构,最后通过在虚拟阵列中构造差异阵列,以L形的线阵结构实现了二维混合MIMO相控阵雷达的功能。通过形成虚拟阵元数目扩展,在保留混合MIMO相控阵雷达优势的同时增大了阵列自由度。且本文给出了这种结构下阵列流形的闭合表达式。仿真结果表明,与传统的混合MIMO相控阵雷达相比,这种方法能够提高自由度和波达方向估计精度。

基因芯片技术及其在畜牧兽医业中的应用概述

基因芯片技术是影响深远的科技发明之一,是生命科学与微电子学等学科互相融合的一门技术。本文概述基因芯片技术的发展历史、原理、类型、优点、操作流程及其在畜牧兽医业中的应用。

Identification of differentially expressed long non-coding RNAs in human ovarian cancer cells with different metastatic potentials

Objective： To identify differentially expressed long non-coding RNAs （lncRNAs） involved in the metastasis of epithelial ovarian cancer. Methods： An in vitro invasion assay was performed to validate the invasive capability of SKOV3 and SKOV3.ip1 cell lines. Total R.NA was then extracted, and microarray analysis was performed. Moreover, nine lncRNAs were selected for validation using RT-qPCR. Results： Compared with the SKOV3 cells, the SKOV3.ip1 cells significantly improved in the in vitro invasive activity. Of the 4,956 lncRNAs detected in the microarra~ 583 and 578 lncRNAs were upregulated and downregulated, respectivel~ in SKOV3.ip1 cells, compared with the parental SKOV3 cells. Seven of the analyzed lncRNAs （MALAT1, H19, UCA1, CCAT1, LOC645249, LOC100128881, and LOC100292680） confirmed the deregulation found by microarray analysis. Conclusion： LncRNAs clusters were differentially expressed in ovarian cancer cells with varying metastatic potentials. This result indicates that some lncRNAs might exert a partial or key role in epithelial ovarian cancer metastasis. Further studies should be conducted to determine the roles of these lncRNAs in ovarian cancer metastasis.

Probiotic Lactobacillus rhamnosus downregulates FCER1 and HRH4 expression in human mast cells

AIM:To investigate the effects of four probiotic bacteria and their combination on human mast cell gene expression using microarray analysis.METHODS:Human peripheral-blood-derived mast cells were stimulated with Lactobacillus rhamnosus (L.rhamnosus) GG (LGG),L.rhamnosus Lc705 (Lc705),Propionibacterium freudenreichii ssp.shermanii JS (PJS) and Bifidobacterium animalis ssp.lactis Bb12 (Bb12) and their combination for 3 or 24 h,and were subjected to global microarray analysis using an Affymetrix GeneChip Human Genome U133 Plus 2.0 Array.The gene expression differences between unstimulated and bacteria-stimulated samples were further analyzed with GOrilla Gene Enrichment Analysis and Visualization Tool and MeV Multiexperiment Viewer-tool.RESULTS:LGG and Lc705 were observed to suppress genes that encoded allergy-related high-affinity IgE receptor subunits α and γ (FCER1A and FCER1G,respectively) and histamine H4 receptor.LGG,Lc705 and the combination of four probiotics had the strongest effect on the expression of genes involved in mast cell immune system regulation,and on several genes that encoded proteins with a pro-inflammatory impact,such as interleukin (IL)-8 and tumour necrosis factor alpha.Also genes that encoded proteins with anti-inflammatory functions,such as IL-10,were upregulated.CONCLUSION:Certain probiotic bacteria might diminish mast cell allergy-related activation by downregulation of the expression of high-affinity IgE and histamine receptor genes,and by inducing a pro-inflammatory response.

Identification of differential gene expressions in colorectal cancer and polyp by cDNA microarray

AIM： TO screen the differential expressed genes in colorectal cancer and polyp tissue samples. METHODS： Tissue specimens containing 16 cases of colorectal adenocarcinoma and colorectal polyp vs nor- mal mucosae were collected and subjected to cDNA microarray and bioinformatical analyses. Quantitative reverse transcription-polymerase chain reaction （qRT- PCR） was used to confirm some of the cDNA microarray data.RESULTS： The experimental data showed that eight genes were differentially expressed, most of which were upregulated in adenomatous polyp lesions. Forty-six genes expressions were altered in colorectal cancers, of which 29 were upregulated and 17 downregulated, as compared to the normal mucosae. In addition, 18 genes were similarly altered in both adenomatous polyps and colorectal cancer, qRT-PCR analyses confirmed the cDNA microarray data for four of those 18 genes： MTA1, PDCD4, TSC1 and PDGFRA. CONCLUSION： These differentially expressed genes likely represent biomarkers for early detection of co- Iorectal cancer and may be potential therapeutic targets after confirmed by further studies.

Analysis of differentially expressed tumor-related genes in Peutz-Jeghers syndrome combined with colorectal carcinoma with cDNA microarrays

Objective:The aim of the study was to screen the differentially expressed genes of Peutz-Jeghers syndrome (PJS) and colorectal carcinoma (CRC).Methods:This study used cDNA microarray to comparatively analyze the gene expression profiles of 4 cases of PJS combined with colorectal adenocarcinoma vs.normal mucosae.The cDNA microarray contained 8064 human genes,and then using RT-PCR to test three genes of all.Results:The experimental data showed that fourteen genes were differentially expressed,which were up-regulated in PJS.Fifty-one genes expressions were altered in CRCs,of which 32 were up-regulated,as compared to the normal mucosae.In addition,5 genes were similarly altered in both PJS and CRCs.RT-PCR analyses confirmed the cDNA microarray data for three of those genes:LATS2,APC and MADH4.Conclusion:LCN2,USP4,GRO3,HYAL1 and APC-these differentially expressed genes likely represent biomarkers for early detection of CRC and may be potential therapeutic targets.

二维嵌套混合MIMO相控阵雷达接收阵列设计

针对二维混合多输入多输出(MIMO)相控阵雷达发射阵列子阵分割带来的自由度损失问题,提出一种基于二维嵌套阵列的二维混合MIMO相控阵雷达接收阵列设计新方法。首先,给出一种由稀疏阵列和密集阵列构成的嵌套阵接收阵列的二维混合MIMO相控阵雷达信号模型;其次,通过对接收信号的协方差矩阵进行Khatri-Rao乘积处理,得到阵元位置差的差异阵列,形成接收阵元数目的虚拟扩展;最后,通过空间平滑处理进行波达方向估计。仿真实验表明,与传统二维混合MIMO相控阵雷达相比,所提方法在不增加实际阵元数目的情况下可以有效扩展虚拟阵元数目,提高雷达阵列自由度,进而提高二维混合MIMO相控阵雷达波达方向估计精度。

Global gene expression profiles for the growth phases of Trichophyton rubrum

Trichophyton rubrum （T. rubrum） is a common superficial fungus. Molecular and genetic studies of T. rubrum are still limited. In this paper, we report the global analysis of gene expression profiles at different growth phases using cDNA microarray technology. A total of 2044 differentially expressed genes were obtained and clustered into three expression patterns. Our data confirmed previous results that many mRNAs were pre-stored in the conidia of T. rubrum. Transcriptional profiling and function analysis showed that some glycolytic enzymes share similar expression patterns and may be coregulated during the transi- tion of growth phases. Some genes involved in small GTPase signaling pathways, and in cAMP-dependent and MAPK regulation pathways were induced in response to the growth dynamics of T. rubrum. Although the detailed biological roles of these Z rubrum genes are still unknown, our results suggest that these genes may be involved in regulation mechanisms in the life cycle of the fungus.