Size Dependent Mechanical Properties of Monolayer Densely Arranged Polystyrene Nanospheres

In contrast to macroscopic materials, the mechanical properties of polymer nanospheres show fascinating scientific and application values. However, the experimental measurements of individual nanospheres and quantitative analysis of theoretical mechanisms remain less well performed and understood. We provide a highly efficient and accurate method with monolayer densely arranged honeycomb polystyrene (PS) nanospheres for the quantitatively mechanical characterization of individual nanospheres on the basis of atomic force microscopy (AFM) nanoindentation. The efficiency is improved by 1–2 orders, and the accuracy is also enhanced almost by half-order. The elastic modulus measured in the experiments increases with decreasing radius to the smallest nanospheres (25–35 nm in radius). A core–shell model is introduced to predict the size dependent elasticity of PS nanospheres, and the theoretical prediction agrees reasonably well with the experimental results and also shows a peak modulus value

qRT-PCR analysis of stress-response genes.

<p>qRT-PCR analysis of stress-response genes.</p

Clusters of Orthologous Group classifications.

<p>Clusters of Orthologous Group classifications.</p

Genome-Scale Transcriptome Analysis of the Desert Shrub <i>Artemisia sphaerocephala</i>

<div><p>Background</p><p><i>Artemisia sphaerocephala</i>, a semi-shrub belonging to the <i>Artemisia</i> genus of the <i>Compositae</i> family, is an important pioneer plant that inhabits moving and semi-stable sand dunes in the deserts and steppes of northwest and north-central China. It is very resilient in extreme environments. Additionally, its seeds have excellent nutritional value, and the abundant lipids and polysaccharides in the seeds make this plant a potential valuable source of bio-energy. However, partly due to the scarcity of genetic information, the genetic mechanisms controlling the traits and environmental adaptation capacity of <i>A</i>. <i>sphaerocephala</i> are unknown.</p><p>Results</p><p>Here, we present the first in-depth transcriptomic analysis of <i>A</i>. <i>sphaerocephala</i>. To maximize the representation of conditional transcripts, mRNA was obtained from 17 samples, including living tissues of desert-growing <i>A</i>. <i>sphaerocephala</i>, seeds germinated in the laboratory, and calli subjected to no stress (control) and high and low temperature, high and low osmotic, and salt stresses. <i>De novo</i> transcriptome assembly performed using an Illumina HiSeq 2500 platform resulted in the generation of 68,373 unigenes. We analyzed the key genes involved in the unsaturated fatty acid synthesis pathway and identified 26 <i>A</i>. <i>sphaerocephala fad2</i> genes, which is the largest <i>fad2</i> gene family reported to date. Furthermore, a set of genes responsible for resistance to extreme temperatures, salt, drought and a combination of stresses was identified.</p><p>Conclusion</p><p>The present work provides abundant genomic information for functional dissection of the important traits of <i>A</i>. <i>sphaerocephala</i> and contributes to the current understanding of molecular adaptive mechanisms of <i>A</i>. <i>sphaerocephala</i> in the desert environment. Identification of the key genes in the unsaturated fatty acid synthesis pathway could increase understanding of the biological regulatory mechanisms of fatty acid composition traits in plants and facilitate genetic manipulation of the fatty acid composition of oil crops.</p></div

GO categories of the <i>Artemisia sphaerocephala</i> unigenes.

<p>GO categories of the <i>Artemisia sphaerocephala</i> unigenes.</p

Fatty acid compositions of different species.

<p>Fatty acid compositions of different species.</p

Additional file 1: Figure S1. of Trichloromethane fraction of Incarvillea compacta induces lytic cytotoxicity and apoptosis in Epstein-Barr virus-positive gastric cancer AGS cells

UHPLC-MS chromatogram profile of dichloromethane fraction of I. compacta. (DOCX 23 kb

Summary of sequence annotation.

<p>Summary of sequence annotation.</p

Plot showing the dependence of unigene length on the number of reads assembled into the corresponding unigenes.

<p>Plot showing the dependence of unigene length on the number of reads assembled into the corresponding unigenes.</p

Overview of <i>de novo</i> sequencing and assembly.

<p>Overview of <i>de novo</i> sequencing and assembly.</p