The influence of porous silicon on axonal outgrowth in vitro.

xonal outgrowth on smooth and porous silicon surfaces was studied in organ culture. The pore size of the silicon substrata varied between 100 and 1500 nm. We found that axons preferred to grow and elongate on porous silicon surfaces only when pores of (150-500 nm) are available.     

Air plasma spray processing and electrochemical characterization of SOFC composite cathodes

Air plasma spraying has been used to produce porous composite cathodes containing (La_0.8Sr_0.2)_0.98MnO_3−y (LSM) and yttria-stabilized zirconia (YSZ) for use in solid oxide fuel cells (SOFCs). Preliminary investigations focused on determining the range of plasma conditions under which each of the individual materials could be successfully deposited. A range of conditions was thereby determined that was suitable for the deposition of a composite cathode from pre-mixed LSM and YSZ powders. A number of composite cathodes were produced using different combinations of parameter values within the identified range according to a Uniform Design experimental grid. Coatings were then characterized for composition and microstructure using EDX and SEM. As a result of these tests, combinations of input parameter values were identified that are best suited to the production of coatings with microstructures appropriate for use in SOFC composite cathodes. A selection of coatings representative of the types of observed microstructures were then subjected to electrochemical testing to evaluate the performance of these cathodes. From these tests, it was found that, in general, the coatings that appeared to have the most suitable microstructures also had the highest electrochemical performances, provided that the deposition efficiency of both phases was sufficiently high.     

减少排碳量五部曲

近年, 社会各界十分关注环保问题.各大报刊杂志封面都以环保报导为主题,环保议题更成为不少新闻节目的焦点.全球暖化与暖化后为气候带来的变迁已是无庸置疑的事实,这些生态问题正威胁着地球上的所有生命.身为地球成员的我们,自然不可置身事外,每一个人都应该为环保出一分力,减少排放CO2,协助抗暖化.     

A Ten-Year Rule to guide the allocation of EU emission allowances

Member States in the European Union (EU) are responsible for National Allocation Plans governing the initial distribution of emission allowances in the CO₂ Emission Trading System, including rules governing allocations to installations that close and to new entrants. The European Commission has provided guidelines to discourage the use of allocation methodologies that provide incentives affecting firms’ compliance behavior, for example by rewarding one type of compliance investment over another. We find that the treatment of closures and new entrants by Member States is inconsistent with the general guidelines provided by the EU. We propose stronger EU guidance regarding closures and new entrants, a more precise compensation criterion on which to justify free allocations, and a Ten-Year Rule as a component of future EU policy that can guide a transition from current practice to an approach that places greater weight on efficiency.     

Adaptive memory search for multidemand multidimensional knapsack problems

We describe a simple adaptive memory search method for the 0/1 Multidemand Multidimensional Knapsack Problem (0/1 MDMKP). The search balances the level of infeasibility against the quality of the solution, and uses a simple dynamic tabu search mechanism. A weighting scheme to balance out the differences in the tightness of the constraints is also implemented. Computational results on a portfolio of test problems taken from the literature are reported, showing very favorable results, both in terms of solution quality and the ability of the search to find feasible solutions.     

One Question,Multiple Answers: Biochemical and Biophysical Screening Methods Retrieve Deviating Fragment Hit Lists

Fragment‐based lead discovery is gaining momentum in drug development. Typically, a hierarchical cascade of several screening techniques is consulted to identify fragment hits which are then analyzed by crystallography. Because crystal structures with bound fragments are essential for the subsequent hit‐to‐lead‐to‐drug optimization, the screening process should distinguish reliably between binders and non‐binders. We therefore investigated whether different screening methods would reveal similar collections of putative binders. First we used a biochemical assay to identify fragments that bind to endothiapepsin, a surrogate for disease‐relevant aspartic proteases. In a comprehensive screening approach, we then evaluated our 361‐entry library by using a reporter‐displacement assay, saturation‐transfer difference NMR, native mass spectrometry, thermophoresis, and a thermal shift assay. While the combined results of these screening methods retrieve 10 of the 11 crystal structures originally predicted by the biochemical assay, the mutual overlap of individual hit lists is surprisingly low, highlighting that each technique operates on different biophysical principles and conditions.     

Aggregation‐Prone Amyloid‐β⋅CuII Species Formed on the Millisecond Timescale under Mildly Acidic Conditions

Metal ions and their interaction with the amyloid beta (Aβ) peptide might be key elements in the development of Alzheimer's disease. In this work the effect of Cu^II on the aggregation of Aβ is explored on a timescale from milliseconds to days, both at physiological pH and under mildly acidic conditions, by using stopped‐flow kinetic measurements (fluorescence and light‐scattering), ¹H NMR relaxation and ThT fluorescence. A minimal reaction model that relates the initial Cu^II binding and Aβ folding with downstream aggregation is presented. We demonstrate that a highly aggregation prone Aβ ? Cu^II species is formed on the sub‐second timescale at mildly acidic pH. This observation might be central to the molecular origin of the known detrimental effect of acidosis in Alzheimer's disease.     

The Influence of Pressure in the Pore System on Fire Spalling of Concrete

Fire spalling of concrete is often attributed to the pressure in the pore system. Recent results from fire tests on Self Compacting Concrete (SCC) have shown that the connection between pressure in the capillary pore system and fire spalling of concrete is not obvious [Jansson (2006) Proceedings from the 4th international workshop, Aveiro, Portugal, pp 747–756]. This issue has been investigated by performing pressure measurements on SCC and a traditional vibrated concrete designed for tunnel construction. In the tests conducted on SCC data from exposure to the hydrocarbon (HC) fire curve are presented. In the tests conducted on vibrated concrete, measurements were performed in concrete exposed to the standard fire curve (EN1363-1) and the Rijkswaterstaat (RWS) curve. The highest pressures in the two test series were measured in the concretes that did not exhibit spalling during fire. One conclusion from the tests is that pressure in the capillary system is not the driving force for spalling during fire exposure. However, pressure is involved in the redistribution of moisture during fire exposure. A new theory is proposed to explain the spalling reducing function of PP-fibres based on the presence and movement of moisture.     

Electroconductive paper prepared by coating with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) and organic solvents

Electroconductive papers were produced by coating commercial base papers with blends of poly(3,4‐ethylenedioxythiophene)/poly(4‐styrenesulfonate) (PEDOT:PSS) and organic solvents. The bulk conductivities of the coated papers were measured using a four‐probe technique. One‐sided and two‐sided coating gave comparable conductivity levels. The presence of sorbitol and isopropanol in the PEDOT:PSS blends did not enhance the bulk conductivity of the coated paper, and with increasing concentrations of these solvents, the conductivity decreased due to dilution of the conducting component. Samples coated with PEDOT:PSS blends containing N‐methylpyrrolidone (NMP) or dimethyl sulfoxide (DMSO) exhibited a higher conductivity than those coated with pure PEDOT:PSS because of their plasticizing effect and conformational changes of PEDOT molecules indicated by the red shift and disappearance of the shoulder peak at about 1442 cm^?1 in the Raman spectra of the coated samples. EDS imaging showed that PEDOT:PSS is distributed throughout the thickness direction of the paper. Contact angle measurements were made to monitor the hydrophilicity of the paper surface and total sulfur analysis was used to determine the amount of PEDOT:PSS deposited onto the paper. The tensile strength of all the paper samples increased slightly after treatment. Thus, it is demonstrated that enhanced bulk conductivity in the order of 10^?3 S/cm can be achieved by using organic conductive materials and surface treatment techniques. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010