Rolling of Al-SiC_p Composites

Aluminum based metal matrix composites are offering o utstanding properties in a number of automotive and aircraft components and body structures. The major advantages of these composite materials are their high st rength to weight ratio, high stiffness, high hardness, wear resistance, low coef ficient of thermal expansion, superior dimensional stability and versatility to designer. In addition to these their isotropic properties, good forming characte ristics, easy availability of cheaper reinforcements...     

Synthesis of the 3D porous carbon-manganese oxide (3D-C@MnO) nanocomposite and its supercapacitor behavior study

A 3D porous carbon-manganese oxide ([email protected]) nanocomposite is successfully synthesized via a thermal plasma deposition method. The chemical bonds and compositions, phase structures, surface morphologies, etc. of as-obtained [email protected] nanocomposite were characterized by the various equipment, such as X-ray diffractometer, X-ray photoelectron spectroscopy, and electron microscopes. The electrochemical performances of the [email protected] nanocomposite electrode showed a specific capacitance of 780 F g^?1 at a current density of 2 A g^?1 and a capacitance retention rate of 99% after 5000 charge-discharge cycles at a high current density of 10 A g^?1. These excellent capacitive performances may be attributed to the encapsulation of MnO nanoparticles by porous carbon sheets in the [email protected] MnO nanocomposite structure. It is believed that the carbon-encapsulated MnO nanoparticles can be protected from a volume deformation during the charge adsorption/desorption cycle and can be electrically improved by the encapsulated carbon sheets, resulting in better overall capacitive performance. In addition, this study also demonstrates the practical applicability by assembling a supercapacitor using the as-obtained [email protected] nanocomposite to glow a light emitting diode.     

Tissue engineering: creation of long-lasting blood vessels

The construction of stable blood vessels is a fundamental challenge for tissue engineering in regenerative medicine. Although certain genes can be introduced into vascular cells to enhance their survival and proliferation, these manipulations may be oncogenic. We show here that a network of long-lasting blood vessels can be formed in mice by co-implantation of vascular endothelial cells and mesenchymal precursor cells, by-passing the need for risky genetic manipulations. These networks are stable and functional for one year in vivo.     

A naturally occurring MTA1 variant sequesters oestrogen receptor-alpha in the cytoplasm

Oestrogen receptor (ER) is a good prognostic marker for the treatment of breast cancers. Upregulation of metastatic tumour antigen 1 (MTA1) is associated with the invasiveness and metastatic potential of several human cancers and acts as a co-repressor of nuclear ER-alpha. Here we identify a naturally occurring short form of MTA1 (MTA1s) that contains a previously unknown sequence of 33 amino acids with an ER-binding motif, Leu-Arg-Ile-Leu-Leu (LRILL). MTA1s localizes in the cytoplasm, sequesters ER in the cytoplasm, and enhances non-genomic responses of ER. Deleting the LRILL motif in MTA1s abolishes its co-repressor function and its interaction with ER, and restores nuclear localization of ER. Dysregulation of human epidermal growth factor receptor-2 in breast cancer cells enhances the expression of MTA1s and the cytoplasmic sequestration of ER. Expression of MTA1s in breast cancer cells prevents ligand-induced nuclear translocation of ER and stimulates malignant phenotypes. MTA1s expression is increased in human breast tumours with no or low nuclear ER. The regulation of the cellular localization of ER by MTA1s represents a mechanism for redirecting nuclear receptor signalling by nuclear exclusion.     

Coordinated multi-point transmission technique in TDD cellular mobile system

小区间干扰是影响未来蜂窝移动通信系统性能的主要因素,如何克服小区间干扰成为系统设计的关键所在。多点协作传输技术通过控制相邻小区之间的干扰,并将原本是干扰的信号转变为有用信息,从理论上突破了单点非协作系统的干扰受限容量,实现了链路可靠性的提高和传输速率的增加。多点协作技术传输技术被认为是降低小区间干扰、提升小区边缘吞吐量和系统吞吐量的更本质更有效的技术。TDD蜂窝移动通信系统中实现多点协作传输技术具有天然的优势：多点协作所需的大量的信道状态信息在TDD系统中通过上下行信道的互易性可以很容易的获得。本文对TDD系统实现多点协作传输的方案以及可能遇到的问题进行了分析,并通过系统仿真结果证明了两者结合所能带来的性能增益。     

Tumour biology: herceptin acts as an anti-angiogenic cocktail

Malignant tumours secrete factors that enable them to commandeer their own blood supply (angiogenesis), and blocking the action of these factors can inhibit tumour growth. But because tumours may become resistant to treatments that target individual angiogenic factors by switching over to other angiogenic molecules, a cocktail of multiple anti-angiogenic agents should be more effective. Here we show that herceptin, a monoclonal antibody against the cell-surface receptor HER2 (for human epidermal growth factor receptor-2; ref. 4), induces normalization and regression of the vasculature in an experimental human breast tumour that overexpresses HER2 in mice, and that it works by modulating the effects of different pro- and anti-angiogenic factors. As a single agent that acts against multiple targets, herceptin, or drugs like it, may offer a simple alternative to combination anti-angiogenic treatments.     

Pathology: cancer cells compress intratumour vessels

The delivery of therapeutic drugs to solid tumours may be impaired by structural and functional abnormalities in blood and lymphatic vessels. Here we provide evidence that proliferating cancer cells cause intratumour vessels to compress and collapse. By reducing this compressive mechanical force and opening vessels, cytotoxic cancer treatments have the potential to increase blood perfusion, thereby improving drug delivery.     

Hot-corrosion behavior of Cr_2O_3–CNT-coated ASTM-SA213-T22 steel in a molten salt environment at 700°C

The present work investigates the hot-corrosion behavior of carbon nanotube(CNT)-reinforced chromium oxide coatings on boiler steel in a molten salt(Na_2SO_4–60 wt%V_2O_5) environment at 700°C under cyclic conditions. The coatings were deposited via the high-velocity oxygen fuel process. The uncoated and coated steel samples were subjected to hot corrosion in a silicon tube furnace at 700°C for 50 cycles. The kinetics of the corrosion behavior was analyzed through mass-gain measurements after each cycle. The corrosion products were analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis techniques. The results revealed that uncoated steel suffered spallation of scale because of the formation of nonprotective Fe_2O_3 scale. The coated steel samples exhibited lower mass gains with better adhesiveness of oxide scale with the steel alloy until the end of exposure. The CNT-reinforced coatings were concluded to provide better corrosion resistance in the hot-corrosion environment because of the uniform dispersion of CNTs in the coating matrix and the formation of protective chromium oxides in the scale.