Experiments on bright field and dark field high energy electron imaging with thick target material

Using a high energy electron beam for the imaging of high density matter with both high spatial-temporal and areal density resolution under extreme states of temperature and pressure is one of the critical challenges in high energy density physics . When a charged particle beam passes through an opaque target, the beam will be scattered with a distribution that depends on the thickness of the material. By collecting the scattered beam either near or off axis, so-called bright field or dark field images can be obtained. Here we report on an electron radiography experiment using 45 MeV electrons from an S-band photo-injector, where scattered electrons, after interacting with a sample, are collected and imaged by a quadrupole imaging system. We achieved a few micrometers (about 4 micrometers) spatial resolution and about 10 micrometers thickness resolution for a silicon target of 300-600 micron thickness. With addition of dark field images that are captured by selecting electrons with large scattering angle, we show that more useful information in determining external details such as outlines, boundaries and defects can be obtained.Comment: 7pages, 7 figure

Variation and Correlation of Erucic Acid, Oleic Acid and Glucosinolate Contents in Brassica rapa Seeds

In order to screen and identify excellent breeding resources and provide basic materials for Brassica rapa breeding, the contents of erucic acid, oleic acid and glucosinolate in 84 samples of B. rapa were determined by near-infrared spectroscopy, and the correlations among them were also analyzed. The results showed that the content of erucic acid and oleic acid were significantly negatively correlated, the contents of erucic acid and glucosinolate were significantly positively correlated, while the contents of oleic acid and glucosinolate were significantly negatively correlated; principal component analysis (PCA) were performed on the population materials, factors 1 and 2 were extracted for plotting, factor 1 and factor 2 could explain 73.7% and 23.2% of the phenotypic variation, respectively; through cluster analysis, 79 materials aggregated to form group I, and 5 special variants deviated from the population. The variation of erucic acid, oleic acid and glucosinolates in B. rapa populations was rich and there was significant correlation. Through cluster analysis, 5 excellent B. rapa breeding materials (No. 32, No. 45, No. 46, No. 50, and No. 59) were screened

Three-Dimensional High-Energy Electron Radiography Method for Static Mesoscale Samples Diagnostics

In this paper, we propose a new method for static mesoscale sample diagnosis using three-dimensional radiography with high-energy electron radiography (HEER). The principle of three-dimensional high-energy electron radiography (TDHEER) is elucidated, and the feasibility of this method is confirmed by start-to-end simulation results. TDHEER is realized by combining HEER with the three-dimensional reconstruction method, by which more information about the samples can be attained, especially regarding the samples’ internal structures. With our study, the internal structures and the three-dimensional positions of the spherical sample are determined with a ~3 μm resolution. We believe that this new method enhances the HEER diagnostic capability and extends its application potential in mesoscale sciences

Exosomes: decreased sensitivity of lung cancer A549 cells to cisplatin.

Exosomes are small extracellular membrane vesicles of endocytic origin released by many cells that could be found in most body fluids. The main functions of exosomes are cellular communication and cellular waste clean-up. This study was conducted to determine the involvement of exosomes in the regulation of sensitivity of the lung cancer cell line A549 to cisplatin (DDP). When DDP was added to A549 cells, exosomes secretion was strengthened. Addition of the secreted exosomes to other A549 cells increased the resistance of these A549 cells to DDP. Upon exposure of A549 to DDP, the expression levels of several miRNAs and mRNAs reportedly associated with DDP sensitivity changed significantly in exosomes; these changes may mediate the resistance of A549 cells to DDP. Exosomes released by A549 cells during DDP exposure decreased the sensitivity of other A549 cells to DDP, which may be mediated by miRNAs and mRNAs exchange by exosomes via cell-to-cell communication. Although the detailed mechanism of resistance remains unclear, we believed that inhibition of exosomes formation and release might present a novel strategy for lung cancer treatment in the future

The Function Role of miR-181a in Chemosensitivity to Adriamycin by Targeting Bcl-2 in Low-Invasive Breast Cancer Cells

Objectives: miR-181a is involved in immunity, metabolism, tumor suppression or carcinogenesis reported by many other studies. However, its role in the development of chemosensitivity to adriamycin in low-invasive breast cancer cells remains unclear. The aim of this study is to define the function role of miR-181a in promoting the efficacy of adriamycin-based neoadjuvant chemotherapy. Methods: Cell survival analysis was detected by Cell Counting Kit-8 assay. Apoptotic cells were quantitatively detected using FITC Annexin V apoptosis Detection Kit I. Bcl-2 protein expression was measured by western blot. Luciferase reporter vector with the putative BCL-2 3' untranslated region (3'UTR) was constructed to explore whether BCL-2 was a direct target gene of miR-181a. Real-time PCR was performed to test the expression of miR-181a and Bcl-2 in the selected breast cancer tissue samples. Results: The down-regulation of miR-181a decreased adriamycin-induced apoptosis in MCF-7 cells. Transfected with miR-181a mimic in cells resulted in the decreased expression of Bcl-2. The alteration of miR-181a expression did not significantly affect the chemosensitivity to adriamycin in MCF-7 and MCF-7/ADR cells with genetic knockout of Bcl-2. miR-181a may suppress Bcl-2 expression by forming imperfect base pairing with the 3'UTR of Bcl-2 gene such that a negative relationship between miR-181a and Bcl-2 in MCF-7 and MCF-7/ADR cells is observed. Conclusions: At least in part, the detection of miR-181a may direct the clinical medication in patients with neoadjuvant chemotherapy because of miR-181a enhanced adriamycin-induced apoptosis via targeting Bcl-2

Galectin-1 : a link between tumor hypoxia and tumor immune privilege

Purpose: To identify a 15-KDa novel hypoxia-induced secreted protein in head and neck squamous cell carcinomas (HNSCC) and to determine its role in malignant progression. Methods: We used surface-enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS) and tandem MS to identify a novel hypoxia-induced secreted protein in FaDu cells. We used immunoblots, real-time polymerase chain reaction (PCR), and enzyme-linked immunoabsorbent assay to confirm the hypoxic induction of this secreted protein as galectin-1 in cell lines and xenografts. We stained tumor tissues from 101 HNSCC patients for galectin-1, CA IX (carbonic anhydrase IX, a hypoxia marker) and CDS (a T-cell marker). Expression of these markers was correlated to each other and to treatment outcomes. Results: SELDI-TOF studies yielded a hypoxia-induced peak at 15 kDa that proved to be galectin-1 by MS analysis. Immunoblots and PCR studies confirmed increased galectin-1 expression by hypoxia in several cancer cell lines. Plasma levels of galectin-1 were higher in tumor-bearing severe combined immunodeficiency (SCID) mice breathing 10% O 2 compared with mice breathing room air. In HNSCC patients, there was a significant correlation between galectin-1 and CA IX staining (P = .01) and a strong inverse correlation between galectin-1 and CDS staining (P = .01). Expression of galectin-1 and CDS were significant predictors for overall survival on multivariate analysis. Conclusion: Galectin-1 is a novel hypoxia-regulated protein and a prognostic marker in HNSCC. This study presents a new mechanism on how hypoxia can affect the malignant progression and therapeutic response of solid tumors by regulating the secretion of proteins that modulate immune privilege. © 2005 by American Society of Clinical Oncology

Influence of exosomes on expression of miRNAs and mRNAs detected in this study.

<p>Expression levels of (A) miRNAs and (B) mRNAs under normal conditions with and without exosome pretreatment. Fold-changes in expression of (C) miRNAs and (D) mRNAs under cisplatin with and without exosome pretreatment. Bars indicate mean ± SD of three replicates. *indicates p<0.05 versus control groups.</p