Zinc Favors Triple-Negative Breast Cancer’s Microenvironment Modulation and Cell Plasticity

Triple-negative breast cancer (TNBC) tends to metastasize to the brain, a step that worsens the patient’s prognosis. The specific hallmarks that determine successful metastasis are motility and invasion, microenvironment modulation, plasticity, and colonization. Zinc, an essential trace element, has been shown to be involved in all of these processes. In this work, we focus our attention on the potential role of zinc during TNBC metastasis. We used MDA-MB-BrM2 (BrM2) cells, a brain metastasis model derived from the parental TNBC cell line MDA-MB-231. Our studies show that BrM2 cells had double the zinc content of MDA-MB-231 cells. Moreover, exploring different metastatic hallmarks, we found that the zinc concentration is especially important in the microenvironment modulation of brain metastatic cells, enhancing the expression of SerpinB2. Furthermore, we show that zinc promotes the tumorigenic capacity of breast cancer stem cells. In addition, by causing a disturbance in MDA-MB-231 zinc homeostasis by overexpressing the Zip4 transporter, we were able to increase tumorigenicity. Nevertheless, this strategy did not completely recapitulate the BrM2 metastatic phenotype. Altogether, our work suggests that zinc plays an important role in the transformative steps that tumoral cells take to acquire tumorigenic potential and niche specificity.     

Flexible and secure computer-based assessment using a single zip disk

Electronic examination systems, which include Internet-based system, require extremely complicated installation, configuration and maintenance of software as well as hardware. In this paper, we present the design and development of a flexible, easy-to-use and secure examination system (e-Test), in which any commonly used computer can be used as a platform for a computer-based assessment. In our scheme, the e-Test program and the other associated data files, which include questions and answers, user registration information and configuration database as well as score files, are all stored in a single Iomega Zip disk. To ensure security, all the data files are encrypted and can only be decrypted by the e-Test program. Also, during initialization, the e-Test program will attempt to detect and identify the globally unique physical address of the network card of the test computer used. Only those computers with a pre-registered network card will be able to run the test program. In addition, the system developed also provides friendly user interfaces for the examiners to change the test questions, adding and deleting student names and computers for the assessment as well as other system parameters. The system developed has been successfully used in a randomized multiple choice examination in a course on analog and digital signals involving more than 5000 full time second-year students.     

Linux+Apache+Php环境下实现Zip、Rar文件解压缩

给出了在Linux Apache Php环境下对Zip、Rar文件解压缩的方法，并对有关函数作出说明。最后还提供了相关测试代码。     

基于EMS时间序列数据的实时全息无损压缩方法的研究与应用

针对时间序列数据库存在压缩实时性差、损失数据精度、压缩比低等缺陷,提出了时间序列数据实时全息无损压缩方法。介绍实时全息无损压缩方法利用差值、异或运算等方式实现时间序列数据的快速、无损的高效压缩过程,并在实验室测试中通过实时全息无损压缩方法和Zip、Lzo压缩算法对120MB的相同时间序列数据文件分别进行正弦数据、递增数据、功率扰动数据和开关量数据压缩测试。测试结果表明,实时全息无损压缩方法的压缩比最高可达到100：1,可实现时间序列数据的无损、高效、快速压缩,具有强大的容错能力。     

Zip压缩文件数据修复技术研究

为修复因网络传输、磁盘损坏、病毒破坏等原因而受损的Zip文件,基于对文件格式和压缩算法的理解,深入讨论在Zip文件格式与数据严重受损情况下,阐述了一种挖掘出其中可用信息的方法,并提出了一种新的受损Zip文件修复技术。实验结果表明,该技术可以达到良好的修复效果。     

Interface crack propagation in porous and time-dependent materials analyzed with discrete models

A model describing the crack propagation at the interface between a rigid substratum and a beam is considered. The interface is modeled using a fiber bundle model (i.e. using a discrete set of elements having a random strength). The distribution of avalanches, defined as the distance over which the crack is propagated under a fixed force, is studied in order to capture the effect of ageing and time-dependent response of the interface. The avalanches depend not only on the statistical distribution of strength but more importantly on time (or displacement) correlations. Namely, local fiber breakage kinetics is related to a correlation length, which sets the size of the fracture process zone which occurs ahead of the crack due to progressive failure. First, a variation of porosity of the interface is considered. It corresponds for instance to diffusion controlled dissolution processes. Interpreting the results in Delaplace et al. [Delaplace A, Roux S, Pijaudier-Cabot G (2001) J Eng Mech 127:646–652], it is shown that the size of the fracture process zone increases with increasing porosity in accordance with experimental observations [Haidar K, Pijaudier-Cabot G, Dubé J-F, Loukili A (2005) Mater Struct 38:201–210]. The creep–fracture interaction is analyzed in the second part of the paper. It is found based on a Maxwell model that the size of the process zone depends on the fracture propagating velocity and on the distribution of forces in the interface due to the interaction between the interface and the rest of the specimen. The observed decrease of the size of the process zone, in creep experiments, compared to the size of the process zone in a time-independent process, is justified by the proposed model for an interface that is less viscous than the rest of the material.     

T-2 Toxin Induces Oxidative Stress at Low Doses via Atf3ΔZip2a/2b-Mediated Ubiquitination and Degradation of Nrf2

T-2 toxin is mainly produced by Fusarium species, which is an extremely toxic mycotoxin to humans and animals. It is well known that T-2 toxin induces oxidative stress, but the molecular mechanism is still unknown. In this study, we found that T-2 toxin significantly promoted reactive oxygen species (ROS) accumulation in MCF-7 cells at low doses which maintains cell viability at least 80%. Further analysis showed that T-2 toxin downregulated the expression of the master regulator of antioxidant defense gene, nuclear factor erythroid 2-related factor (Nrf2), and its targeted antioxidant genes. Overexpression of Nrf2 or its target gene heme oxygenase 1 (HO1) significantly blocked the ROS accumulation in MCF-7 cells under T-2 toxin treatment. Moreover, we found that T-2 toxin downregulated the antioxidant genes via inducing the expression of ATF3ΔZip2a/2b. Importantly, overexpression of ATF3ΔZip2a/2b promoted the ubiquitination and degradation of Nrf2. Altogether, our results demonstrated that T-2 toxin-induced ROS accumulation via ATF3ΔZip2a/2b mediated ubiquitination and degradation of Nrf2, which provided a new insight into the mechanism of T-2 toxin-induced oxidative stress.     

Urban American Landscape

Landscape architecture has emerged from the deep sleep it entered during the Modernist period and remained in for most of the 20th century. Now, valued because of the environmental movement, stimulated by collaborations with architects and artists, and presented with opportunities to transform abandoned industrial sites, landscape architects are enthusiastically producing new kinds of parks on brownfields, along waterfronts, even on rooftops and in garbage dumps. Jayne Merkel here looks at ways the designed landscape is creating outdoor public space in a country where it has not always been valued. Copyright © 2007 John Wiley & Sons, Ltd.     

基于EMS时间序列数据的实时全息无损压缩方法的研究与应用

针对时间序列数据库存在压缩实时性差、损失数据精度、压缩比低等缺陷,提出了时间序列数据实时全息无损压缩方法。介绍实时全息无损压缩方法利用差值、异或运算等方式实现时间序列数据的快速、无损的高效压缩过程,并在实验室测试中通过实时全息无损压缩方法和Zip、Lzo压缩算法对120 MB的相同时间序列数据文件分别进行正弦数据、递增数据、功率扰动数据和开关量数据压缩测试。测试结果表明,实时全息无损压缩方法的压缩比最高可达到100∶1;可实现时间序列数据的无损、高效、快速压缩,具有强大的容错能力。