Allotransplantation of adult spinal cord tissues after complete transected spinal cord injury: Long-term survival and functional recovery in canines

Science China Life Sciences - Spinal cord injury (SCI), especially complete transected SCI, leads to loss of cells and extracellular matrix and functional impairments. In a previous study, we...     

Terahertz Selective Emission Enhancement from a Metasurface-Coupled Photoconductive Emitter in Quasi-Near-Field Zone

We present a THz emission enhancement of 41 times at 0.92 THz from a metasurface made of T-shaped resonators excited in a quasi-near-field zone. Such a metasurface has an intrinsic transmission minimum with Q factor of 4 at 1.25 THz under far-field excitation. When this metasurface is coupled onto the backside of a 625-μm-thick photoconductive emitter, the metasurface is below the Fraunhofer distance to the excitation source. As such, one broad enhancement around 0.47 THz and another extremely narrow enhancement at 0.92 THz in the emission spectrum are observed owing to a quasi-near-field excitation. Theoretically, the Q factor of the latter is up to 307, which is limited by the spectral resolution in experiment. The numerical simulations indicate that the T-shaped resonators serve as an array of plasmonic antennas resulting in the aforementioned emission enhancement of THz radiation.

     

Status of water environment pollution in the Xixi Wetland and its ecological treatment countermeasures

In this paper,the water quality of the Xixi Wetland was evaluated and the characteristics of water pollution were described according to the survey data.Based on the status of water quality and its functional requirements as an urban wetland,biological-ecological countermeasures were suggested.The experimental use of ecological technologies,such as artificial wetlands,ecological aquiculture and artificial floating island,were done in several fish ponds in the Xixi Wetland.Water monitoring results show that the quality of the treated water has improved significantly and the measures to purify the eutrophic water in the wetland have been effective.     

Subspecies-specific intron length polymorphism markers reveal clear genetic differentiation in common wild rice （Oryza rufipogon L.） in relation to the domestication of cultivated rice （O. sativa L.）

It is generally accepted that Oryza rufipogon is the progenitor of Asian cultivated rice （O. sativa）. However, how the two subspecies of O. sativa （indica and japonica） were domesticated has long been debated. To investigate the genetic differentiation in O. rufipogon in relation to the domestication of O. sativa, we developed 57 subspecies-specific intron length polymorphism （SSILP） markers by comparison between 10 indica cultivars and 10 japonica cultivars and defined a standard indica rice and a standard japonica rice based on these SSILP markers. Using these SSILP markers to genotype 73 O. rufipogon accessions, we found that the indica alleles and japonica alleles of the SSILP markers were predominant in the O. rufipogon accessions, suggesting that SSILPs were highly conserved during the evolution of O. sativa. Cluster analysis based on these markers yielded a dendrogram consisting of two distinct groups： one group （Group I） comprises all the O. rufipogon accesions from tropical （South and Southeast） Asia as well as the standard indica rice; the other group （Group II） comprises all the O. rufipogon accessions from Southern China as well as the standard japonica rice. Further analysis showed that the two groups have significantly higher frequencies of indica alleles and japonica alleles, respectively. These results support the hypothesis that indica rice and japonica rice were domesticated from the O. rufipogon of tropical Asia and from that of Southern China, respectively, and suggest that the indica-japonica differentiation should have formed in O. rufipogon long before the beginning of domestication. Furthermore, with an O. glaberrima accession as an outgroup, it is suggested that the indica-japonica differentiation in O. ruffpogon might occur after its speciation from other AA-genome species.     

A platform to standardize,store, and visualize proteomics experimental data

With the development of functional genomics research, large-scale proteomics studies are now widespread, presenting significant challenges for data storage, exchange, and analysis. Here we present the Integrated Proteomics Exploring Database （IPED） as a platform for managing proteomics experimental data （both process and result data）. IPED is based on the schema of the Proteome Experimental Data Repository （PEDRo）, and complies with the General Proteomics Standard （GPS） drafted by the Proteomics Standards Committee of the Human Proteome Organization. In our work, we developed three components for the IPED platform： the IPED client editor, IPED server software, and IPED web interface. The client editor collects experimental data and generates an extensible markup language （XML） data file compliant with PEDRo and GPS; the server software parses the XML data file and loads information into a core database; and the web interface displays experimental results, to provide a convenient graphic representation of data. Given software convenience and data abundance, IPED is a powerful platform for data exchange and presents an important resource for the proteomics community. In its current release, IPED is available at http：//www. biosino.org/iped2.     

基于复合叶片特征的计算机植物识别方法

该文探讨如何根据植物的叶片特征,利用图像处理和机器学习的方法对植物进行分类。鉴于现有的叶片分类系统多采用单一的特征,如几何和纹理等,仅能在小规模数据库上得到较好的结果。然而,随着样本种类的增多,单一特征在不同种类叶片之间的相似性非常明显,致使分类正确率降低。该研究使用多种复合特征,并提出了原创的预处理方法以及宽度、叶缘频率特征,较传统的几何特征更为详尽。研究结果显示,复合特征可以有效避免算法过拟合问题,使之适用于更大的数据库。通过提取21类植物的叶片宽度、颜色、叶缘和纹理共292维特征,对1 915张数字图像进行了分类,正确率达到93%,并分析了各类特征对分类结果的影响。研究结果表明,在不影响分类正确率前提下,可将特征减少到约100维。     

Genetic map of Triticum turgidum based on a hexaploid wheat population without genetic recombination for D genome

ABSTRACT: BACKGROUND: A synthetic doubled-haploid hexaploid wheat population, SynDH1, derived from the spontaneous chromosome doubling of triploid F1 hybrid plants obtained from the cross of hybrids Triticum turgidum ssp. durum line Langdon (LDN) and ssp. turgidum line AS313, with Aegilops tauschii ssp. tauschii accession AS60, was previously constructed. SynDH1 is a tetraploidization-hexaploid doubled haploid (DH) population because it contains recombinant A and B chromosomes from two different T. turgidum genotypes, while all the D chromosomes from Ae. tauschii are homogenous across the whole population. This paper reports the construction of a genetic map using this population. RESULTS: Of the 606 markers used to assemble the genetic map, 588 (97%) were assigned to linkage groups. These included 513 Diversity Arrays Technology (DArT) markers, 72 simple sequence repeat (SSR), one insertion site-based polymorphism (ISBP), and two high-molecular-weight glutenin subunit (HMW-GS) markers. These markers were assigned to the 14 chromosomes, covering 2048.79 cM, with a mean distance of 3.48 cM between adjacent markers. This map showed good coverage of the A and B genome chromosomes, apart from 3A, 5A, 6A, and 4B. Compared with previously reported maps, most shared markers showed highly consistent orders. This map was successfully used to identify five quantitative trait loci (QTL), including two for spikelet number on chromosomes 7A and 5B, two for spike length on 7A and 3B, and one for 1000-grain weight on 4B. However, differences in crossability QTL between the two T. turgidum parents may explain the segregation distortion regions on chromosomes 1A, 3B, and 6B. CONCLUSIONS: A genetic map of T. turgidum including 588 markers was constructed using a synthetic doubled haploid (SynDH) hexaploid wheat population. Five QTLs for three agronomic traits were identified from this population. However, more markers are needed to increase the density and resolution of this map in the future study.     

Hepato-specific microRNA-122 facilitates accumulation of newly synthesized miRNA through regulating PRKRA

microRNAs (miRNAs) are a versatile class of non-coding RNAs involved in regulation of various biological processes. miRNA-122 (miR-122) is specifically and abundantly expressed in human liver. In this study, we employed 3'-end biotinylated synthetic miR-122 to identify its targets based on affinity purification. Quantitative RT-PCR analysis of the affinity purified RNAs demonstrated a specific enrichment of several known miR-122 targets such as CAT-1 (also called SLC7A1), ADAM17 and BCL-w. Using microarray analysis of affinity purified RNAs, we also discovered many candidate target genes of miR-122. Among these candidates, we confirmed that protein kinase, interferon-inducible double-stranded RNA-dependent activator (PRKRA), a Dicer-interacting protein, is a direct target gene of miR-122. miRNA quantitative-RT-PCR results indicated that miR-122 and small interfering RNA against PRKRA may facilitate the accumulation of newly synthesized miRNAs but did not detectably affect endogenous miRNAs levels. Our findings will lead to further understanding of multiple functions of this hepato-specific miRNA. We conclude that miR-122 could repress PRKRA expression and facilitate accumulation of newly synthesized miRNAs.     

鸡视网膜母细胞瘤基因1(RB1)多态性与体重性状的相关性

为探讨鸡视网膜母细胞瘤基因1(Retinoblastoma1,RB1)多态性对体重性状的影响,文章以东北农业大学高、低脂双向选择品系肉鸡为实验材料,采用MALDI-TOF-MS、PCR-RFLP方法进行基因多态性检测和个体基因型分析,共获得27个SNP位点的基因型数据。采用滑动窗口法构建单倍型,进而利用单位点和单倍型分别与鸡体重性状进行关联分析。结合单位点和单倍型分析结果,确定了RB1基因上4个显著影响1周龄体重的SNP位点,2个显著影响1、3周龄体重的SNP位点。研究结果表明RB1基因是影响鸡早期体重性状的重要候选基因。