Interleukin-1beta-induced cyclooxygenase-2 expression requires activation of both c-Jun NH2-terminal kinase and p38 MAPK signal pathways in rat renal mesangial cells

The inflammatory cytokine interleukin-1beta (IL-1beta) induces cyclooxygenase-2 (Cox-2) expression with a concomitant release of prostaglandins from glomerular mesangial cells. We reported previously that IL-1beta rapidly activates the c-Jun NH2-terminal/stress-activated protein kinases (JNK/SAPK) and p38 mitogen-activated protein kinase (MAPK) and also induces Cox-2 expression and prostaglandin E2 (PGE2) production. The current study demonstrates that overexpression of the dominant negative form of JNK1 or p54 JNK2/SAPKbeta reduces Cox-2 expression and PGE2 production stimulated by IL-1beta. Similarly, overexpression of the kinase-dead form of p38 MAPK also inhibits IL-1beta-induced Cox-2 expression and PGE2 production. These results suggest that activation of both JNK/SAPK and p38 MAPK is required for Cox-2 expression after IL-1beta activation. Furthermore, our experiments confirm that IL-1beta activates MAP kinase kinase-4 (MKK4)/SEK1, MKK3, and MKK6 in renal mesangial cells. Overexpression of the dominant negative form of MKK4/SEK1 decreases IL-1beta- induced Cox-2 expression with inhibition of both JNK/SAPK and p38 MAPK phosphorylation. Overexpression of the kinase-dead form of MKK3 or MKK6 demonstrated that either of these two mutant kinases inhibited IL-1beta-induced p38 MAPK phosphorylation and Cox-2 expression but not JNK/SAPK phosphorylation and activation. This study suggests that the activation of both JNK/SAPK and p38 MAPK signaling cascades is required for IL-1beta-induced Cox-2 expression and PGE2 synthesis.     

Controlled Intracellular Release of Peptides from Microcapsules Enhances Antigen Presentation on MHC Class I Molecules

To understand the time course of action of any small molecule inside a single cell, one would deposit a defined amount inside the cell and initiate its activity at a defined moment. An elegant way to achieve this is to encapsulate the molecule in a micrometer‐sized reservoir, introduce it into a cell, remotely open its wall by a laser pulse, and then follow the biological response by microscopy. The validity of this approach is validated here using microcapsules with defined walls that are doped with metallic nanoparticles so as to enable them to be opened with an infrared laser. The capsules are loaded with a fluorescent antigenic peptide and introduced into mammalian cultured cells where, upon laser‐induced release, the peptide binds to major histocompatibility complex (MHC) class I proteins and elicits their cell surface transport. The concept of releasing a drug inside a cell and following its action is applicable to many problems in cell biology and medicine.     

同步多媒体互连方案实现低功耗高性能的手机设计

随着移动通信技术愈趋发达与先进,高端手机和移动终端设备正迅速成为消费者主要用于处理通信、信息、甚至个人财务管理和娱乐中心的工具。根据市场调查机构iSuppli的报告     

Electro-bioremediation of hydrophobic organic soil-contaminants: A review of fundamental interactions

In recent years, there has been increasing interest in employing electro-bioremediation, a hybrid technology of bioremediation and electrokinetics for the treatment of soil contaminated with hydrophobic organic compounds (HOC). Present electro-bioremediation approaches however mainly aim at pollutant extraction through transport over large distances and tend to neglect both the impact of direct current (DC) on organism-soil interactions and microscale HOC release rates. Accordingly, no data are available on bioavailability changes acting via DC-driven effects on organism-compound and organism-soil interactions. This is a serious gap of our current knowledge hampering the improvement of the electro-bioremediation methodology. This review establishes a conceptual framework of the various influences of DC on processes governing HOC-bioavailability in soil, in particular the DC influence on microbial physiology and the physico-chemistry of organism-soil and organism-compound interactions.     

Simple stabilizing matrices for the computation of compressible flows in primitive variables

The key ingredient that balances stability and accuracy in stabilized formulations is the parameter of intrinsic time-scales. For multi-dimensional hyperbolic systems of equations, this parameter is a matrix and the available expressions for its computation involve the solution of an eigenvalue problem, which can be tedious or cpu time consuming. Thus, for formulations based on primitive variables including pressure, a couple of simple stabilizing matrices are presented which are easy to implement and cpu-economic. Numerical evaluations show the performance of the various choices.     

Process–Structure Map for Diamond‐Like Carbon Fibers from Ethene at Hyperbaric Pressures

High‐pressure laser chemical vapor deposition (HP‐LCVD) is a powerful tool for growing complex microstructures at rapid rates. Not only is it possible to deposit functionally graded materials, but new metastable phases, alloys, and composite materials may be realized. In this paper, the diversity of microstructures that may be obtained through HP‐LCVD is demonstrated, including the growth of metastable materials, e.g., diamond‐like carbon (DLC). For the first time, a pressure–temperature (P–T) phase diagram has been created for HP‐LCVD, identifying nine distinct material phases of carbon from ethene. Regions of high sp³ content are identified via Raman spectroscopy. The kinetics, rate limitations, and thermodynamics of the process are also characterized at hyperbaric pressures, creating a first‐ever process‐rate map—covering the entire useful pressure range for ethene. Thermodynamically enhanced growth is also documented for the first time, where the contribution of the heat of reaction is much greater than the incident laser power—demonstrating a quasi‐self‐sustaining reaction. Finally, sufficient information is provided to reconstruct specific fiber geometries, structures, and growth rates for potential industrial production of carbon fibers from the gas phase.