Thermal conductivity of deformed carbon nanotubes

We investigate the thermal conductivity of four types of deformed carbon nanotubes by using the nonequilibrium molecular dynamics method. It is reported that various deformations have different influence on the thermal properties of carbon nanotubes. For the bending carbon nanotubes, the thermal conductivity is independent on the bending angle. However, the thermal conductivity increases lightly with XY-distortion and decreases rapidly with Z-distortion. The thermal conductivity does not change with the screw ratio before the breaking of carbon nanotubes but decreases sharply after the critical screw ratio.Comment: 6figure

Single Cell Profiling of Circulating Tumor Cells: Transcriptional Heterogeneity and Diversity from Breast Cancer Cell Lines

BACKGROUND: To improve cancer therapy, it is critical to target metastasizing cells. Circulating tumor cells (CTCs) are rare cells found in the blood of patients with solid tumors and may play a key role in cancer dissemination. Uncovering CTC phenotypes offers a potential avenue to inform treatment. However, CTC transcriptional profiling is limited by leukocyte contamination; an approach to surmount this problem is single cell analysis. Here we demonstrate feasibility of performing high dimensional single CTC profiling, providing early insight into CTC heterogeneity and allowing comparisons to breast cancer cell lines widely used for drug discovery. METHODOLOGY/PRINCIPAL FINDINGS: We purified CTCs using the MagSweeper, an immunomagnetic enrichment device that isolates live tumor cells from unfractionated blood. CTCs that met stringent criteria for further analysis were obtained from 70% (14/20) of primary and 70% (21/30) of metastatic breast cancer patients; none were captured from patients with non-epithelial cancer (n = 20) or healthy subjects (n = 25). Microfluidic-based single cell transcriptional profiling of 87 cancer-associated and reference genes showed heterogeneity among individual CTCs, separating them into two major subgroups, based on 31 highly expressed genes. In contrast, single cells from seven breast cancer cell lines were tightly clustered together by sample ID and ER status. CTC profiles were distinct from those of cancer cell lines, questioning the suitability of such lines for drug discovery efforts for late stage cancer therapy. CONCLUSIONS/SIGNIFICANCE: For the first time, we directly measured high dimensional gene expression in individual CTCs without the common practice of pooling such cells. Elevated transcript levels of genes associated with metastasis NPTN, S100A4, S100A9, and with epithelial mesenchymal transition: VIM, TGFß1, ZEB2, FOXC1, CXCR4, were striking compared to cell lines. Our findings demonstrate that profiling CTCs on a cell-by-cell basis is possible and may facilitate the application of 'liquid biopsies' to better model drug discovery

Nanoimprint Lithography 20 Years On

To celebrate the 20th anniversary of nanoimprint lithography (NIL) we present a perspective of how the technique and its prospects have evolved over the past two decades. We describe how it overcame certain fabrication challenges at the time it was first reported and look at some of the obstacles that hindered uptake in industry initially, as well as likely sectors for future successful commercial deployment. Developments in the technique since that are making NIL increasingly attractive such as \u27moving roll to roll\u27 for higher throughput, are also described

Strip: A Soft Real-Time Main Memory Database for Open Systems

Traditionally, real-time systems have been used in control applications, such as plant control and flight control. These applications have stringent timing requirements and missing even a single deadline can be disastrous. Currently, however, there is interest in real-time capabilities from other types of applications. Many problems in telecommunications, program trading, and multimedia delivery require systems that are cognizant of the temporal aspects of both data and transactions. Traditional hard real-time systems, which require very predictable execution times and mostly periodic workloads, do not map well to these event driven applications. This dissertation considers the database facilities that are needed by the new class of applications requiring soft real-time constraints, focusing on two problem in particular. The first problem is how to integrate soft real-time databases (SRTDBs) into distributed systems composed of real-time and non-real-time database systems. Supporting d..