CD26 Induces Colorectal Cancer Angiogenesis and Metastasis through CAV1/MMP1 Signaling

CD26 has been reported as a marker for colorectal cancer stem cells endowed with tumor-initiating properties and capable of colorectal cancer (CRC) metastasis. In this study, we investigated the functional effect of CD26 on CRC angiogenesis and metastasis, and the potential underlying mechanism. The functional effects of CD26 overexpression or repression were determined by a wound healing experiment, and cell migration and invasion assays in vitro and in mouse models. Differentially expressed genes regulated by CD26 were identified by genome-wide mRNA expression array and validated by quantitative PCR. CD26 functionally regulated CRC cell migration and invasion in vitro and angiogenesis and metastasis in vivo. Genome-wide mRNA expression array and qPCR showed that MMP1 was up-regulated in CD26+ subpopulation, and a subsequent experiment demonstrated the regulatory effect of CD26 on MMP1 in CRC cell lines with CD26 repression or overexpression. Furthermore, overexpression of CAV1 abrogated the CD26-regulated MMP1 induction in CRC cell lines. This study demonstrated the functional roles of CD26 in inducing CRC migration, invasion, angiogenesis and metastasis and identified the potential involvement of MMP1 and CAV1 in such process. CD26 is an attractive therapeutic target for combating tumor progression to improve the prognosis of CRC patients.     

Porous composites of hydroxyapatite‐filled poly[ethylene‐co‐(vinyl acetate)] for tissue engineering

A novel porous composite of hydroxyapatite/poly[ethylene‐co‐vinyl acetate)] (HAP/EVA) having better osteointegration was fabricated by gas foaming technique using a non toxic gas blowing agent intended for bone replacement applications. Combined techniques of scanning electronic microscopy (SEM) and X‐ray microcomputed tomography (µCT) analysis showed that the pore size and pore volume of the porous composite decrease with the increase of HAP content. The gravimetric analysis evidenced for good pore interconnectivity within the porous composites. Energy dispersive X‐ray analysis (EDX) studies inveterated the even scattering of Ca ions which in turn indicate the uniform dispersion of HAP particles in the composites. The significant gradation in Ca ion concentration seen in EDX studies is well accordance with the amount of HAP loading in the sample. Mechanical properties of the porous composite having different HAP content were measured to have the compressive strength varying from 1.06 to 2.2 MPa. Non‐cytotoxic character of the material was observed by the cytocompatibility studies. The metabolic activity of L929 cells seeded on the material assessed by [3‐(4,5‐dimethylthiazol)‐2‐yl]‐2,5‐diphenyltertrazolium bromide (MTT) assay was found to be 91.8%. The adhesion and migration of the cells inside the pore walls were visualized by confocal microscopy. Copyright © 2010 Society of Chemical Industry     

美工常用硬件参数面面观

对于一个从事计算机图形方面工作的美术工作者来说，手中的电脑无疑是工作中的左膀右臂。而其在图形图像方面的处理能力则是美工最关注的。借本次专题企划介绍美工相关硬件之机，笔者将一些显卡、绘图板、扫描仪的相关参数向读者朋友们做一介绍，希望能对各位的日常采购有所帮助。     

浅谈图形工作站的选购

图形工作站主要被用于CAD（辅助图形设计）、DCC（数字内容创作）、虚拟仿真以及一些后期制作和特殊的研究领域（比如医学）。比起普通PC，图形工作站属于相对高端的产品．也正因为如此．它一直蒙着神秘的面纱．让普通消费者仿若隔湖观花、看不真切。     

我来教你榨——比WinRAB还强的UHARC GUI

在日常的电脑操作中，我们常常需要将一些大文件进行压缩保存或者传送给其他人，WinRAR是我们使用最多的一个压缩工具，但是WinRAR压缩比并不高．往往压缩后的文件并没有多大改变．有没有一个工具能真正实现高倍压缩呢?这里就为大家介绍一款比WinRAR还强的“世界上压缩比最高”的软件——UHARC GUI，它能够“榨”干你文件中的“水分”，真正实现“浓缩的都是精华”！     

First-Order Reliability Method for Probabilistic Liquefaction Triggering Analysis Using CPT

The potential for liquefaction triggering of a soil under a given seismic loading is measured herein by probability of liquefaction. The first order reliability method (FORM) is used to calculate reliability index, from which the probability of liquefaction is obtained. This approach requires the knowledge of parameter and model uncertainties; the latter is the focus of this paper. An empirical model for determining liquefaction resistance based on cone penetration test (CPT) is established through “neural network learning” of case histories. This resistance model along with a reference seismic loading model forms a performance function or limit state for liquefaction triggering analysis. Within the framework of the FORM, the uncertainty of this limit state model is characterized through an extensive series of sensitivity studies using Bayesian mapping functions that have been calibrated with a set of quality case histories. In addition, a deterministic model for assessing liquefaction potential in terms of factor of safety is presented, and the probability-safety factor mapping functions for estimating the probability of liquefaction for a given factor of safety in the absence of the knowledge of parameter uncertainty are also established. Examples are presented to illustrate the proposed methods.     

Fabrication of Integrated Vertical Mirror Surfaces and Transparent Window for Packaging MEMS Devices

A scheme for creating metal-coated vertical mirrors in silicon, along with an integrated transparent package lid for assembling, packaging, and testing microelectromechanical systems (MEMS) devices is presented. Deep reaction ion etching (DRIE) method described here reduces the loading effect and maintains a uniform etch rate resulting in highly vertical structures. A novel self-masking lithography and liftoff process was developed to ensure that the vertical mirrors undergo uniform metallization while leaving a transparent window for optical probing. Front side of a Si wafer was shallow-etched using DRIE to define an eventual optical window. This surface was then anodically bonded to a Pyrex wafer. Backside Si was then patterned to define thin channels around the optical window. These channels were vertically etched using DRIE, after which the unattached portions of the window region were removed. Negative photoresist was spun on the remaining vertical structures and the stack was exposed from the Pyrex side using Si structures as a self-mask. Subsequent metal sputtering and liftoff results in the metallized top and mirror sidewalls while leaving a clear window. These integrated mirrors and lids are then bonded to the active MEMS mirrors. Various processes and results are illustrated with an example of packaged corner cube retroreflectors (CCRs)     

Synthesis and characterization of novel octa-arm star-block thermoplastic elastomers consisting of poly (p-chlorostyrene-b-isobutylene) arms radiating from a calix[8]arene core

The synthesis and characterization of novel octa-arm star-blocks consisting of poly(p-chlorostyrene-b-isobutylene) (PpClSt-b-PIB) arms radiating from a calix[8]arene (C8) core are described. The synthesis was accomplished by living isobutylene (IB) polymerization induced by a novel octafunctional calix[8]arene derived initiator 1, followed by addition and living polymerization of p-chlorostyrene (pClSt). This sequential block copolymerization method allowed for precise molecular weight control of both polymeric blocks and thus gave rise to star-block thermoplastic elastomers (TPE) with an outstanding combination of mechanical and thermal properties, i.e., high tensile strengths (22 – 27 MPa) and elongations (∼500 %). Differential scanning calorimetry (DSC) indicated microphase separation into glassy PpClSt (T_g= 129°C) and rubbery PIB (T_g=−66°C) domains, and transmission electron microscopy (TEM) indicated that the PpClSt domains are dispersed in the PIB matrix. Received: 1 April 1998/Revised version: 1 June 1998/Accepted: 2 June 1998     

Cationic polymerizations at elevated temperatures by novel initiating systems having weakly coordinating counteranions 2. Isobutylene/isoprene copolymerizations

As a sequel to our studies on isobutylene (IB) homopolymerizations, we have investigated the copolymerization of IB/isoprene (IP) mixtures containing up to ∼20 mole% IP in the feed by the use of the in situ (CH₃)₃Si[B(C₆F₅)₄] initiating system in close-to-neat monomers in the temperature range from −35 to −8 (reflux)°C. The effects of temperature and IB/IP feed ratio on copolymer molecular weights were determined and compared with those produced by AlCl₃. The molecular weights of butyl rubbers obtained by the novel initiating system under a variety of conditions are invariably and significantly higher than those made with AlCl₃. High molecular weight gel-free rubbers containing up to ∼5 mol% unsaturation can be obtained at relatively high temperatures. Copolymer compositions can be controlled by the IB/IP ratio in the feed. Product molecular weights decrease with increasing IP content. To gain insight into the copolymerization mechanism, the activation enthalpy of molecular weights (ΔH^‡=−5.9 kcal/mol, −24.7 kJ/mol) and the reactivity ratios (r_IB= 1.8, r_IP= 1.5) have been determined. Received: 8 July 1998/Revised version: 16 October 1998/Accepted: 16 October 1998