Fluorescent Polyimide Films Produced with Diatomite and Mesoporous Silica as Promising High-Tech Material

Journal of Inorganic and Organometallic Polymers and Materials - Due to their excellent properties, polymides (PIs) result promising as high-performance materials in different technological fields....     

Innovation Performance and International Knowledge Spillovers: Evidence from the Renewable Energy Sector in OECD Countries

This paper aims at evaluating the sources of differences among countries' innovative performances in the renewable energy (RE) sector. Namely, we focus on the national innovative capacity, the knowledge developed abroad and the related knowledge spillovers. We claim that a country is more likely to develop RE innovation: (i) the larger the knowledge stocks of other countries in the same sector; (ii) especially when those other countries share established linkages with the focal country. Relying on a knowledge production function, we model country-level innovative performances in the RE sector for 18 OECD countries in the period 1990–2006. Our findings confirm that, once controlling for climate-energy policies, international knowledge spillovers contribute significantly to RE innovation, and their effect is comparable with domestic R&D and human capital. In addition, international spillovers are more likely if countries share stronger linkages.     

Study of hydrogen physisorption on nanoporous carbon materials of different origin

Hydrogen adsorption capabilities of different nanoporous carbon, i.e. amorphous carbons obtained by chemical activation (with KOH) of a sucrose-derived char previously ground by ball milling and carbon replicas of NH₄-Y and mesocellular silica foam (MSU-F) inorganic templates, were measured and correlated to their porous properties. The porous texture of the prepared carbon materials was studied by means of N₂ and CO₂ adsorption isotherms measured at −196 °C and 0 °C, respectively. Comparison with nanoporous carbons obtained without pre-grinding the sucrose-derived char [12] shows that the ball milling procedure favours the formation of highly microporous carbon materials even at low KOH loadings, having a beneficial effect of the interaction between the char particles and the activating agent. Hydrogen adsorption isotherms at −196 °C were measured in the 0.0-1.1 MPa pressure range, and a maximum hydrogen adsorption capacity of 3.4 wt.% was obtained for the amorphous carbon prepared by activation at 900 °C with a KOH/char weight ratio of 2. Finally, a linear dependence was found between the maximum hydrogen uptake at 1.1 MPa and the samples microporous volume, confirming previous results obtained at −196 °C and sub-atmospheric pressure [12].     

Variable‐temperature IR spectroscopic studies of CO adsorbed on Na‐ZSM‐5 and Na‐Y zeolites

CO interacts with extraframework alkali metal cations (M⁺=) of zeolites to form both M⁺CO and M⁺OC species. By using variabletemperature FTIR spectroscopy, these Cbonded and Obonded species were found to be in a temperaturedependent equilibrium. For the same cation, the difference in interaction energy depends upon the zeolite framework. Thus, for the equilibrium process ZNa⁺=CO ZNa⁺OC, where Z represents the zeolite framework, H ⁰ was found to take the values 3.8 and 2.4 kJ mol^– for CO/NaZSM5 and CO/NaY, respectively. The Cbonded species show always the highest cation–CO interaction energy.     

Interleukin 10 (IL-10) upregulates functional high affinity IL-2 receptors on normal and leukemic B lymphocytes

Interleukin 10 (IL-10) has recently been shown to induce normal human B lymphocytes to proliferate and differentiate into immunoglobulin (Ig)-secreting cells. Herein, we show that IL-10 also promotes DNA synthesis and IgM production by anti-CD40 activated B cell chronic lymphocytic leukemia (B-CLL). Most strikingly, IL-2 and IL-10 were found to synergize to induce the proliferation and differentiation of B-CLL cells. This synergy between IL-2 and IL-10 was also observed with normal B cells which proliferated strongly and secreted large amounts of IgM, IgG, and IgA. The observed synergy is likely to be due to the IL-10-induced increase of high affinity IL-2 receptors on both normal and leukemic B cells. This increase of high affinity receptor is associated to an increase of Tac/CD25 expression that can be detected by flow cytometric analysis. Taken together, these results indicate that IL-10 permits anti-CD40 activated B cells to respond to IL-2 through an induction of high affinity IL-2 receptors. This effect of IL-10 may partly explain how T cells, which activate B cells in a CD40-dependent fashion, induce B cell proliferation and differentiation mostly through IL-2.     

Targeting Serotonin 2A and Adrenergic α1 Receptors for Ocular Antihypertensive Agents: Discovery of 3,4‐Dihydropyrazino[1,2‐b]indazol‐1(2H)‐one Derivatives

Glaucoma affects millions of people worldwide and causes optic nerve damage and blindness. The elevation of the intraocular pressure (IOP) is the main risk factor associated with this pathology, and decreasing IOP is the key therapeutic target of current pharmacological treatments. As potential ocular hypotensive agents, we studied compounds that act on two receptors (serotonin 2A and adrenergic α₁) linked to the regulation of aqueous humour dynamics. Herein we describe the design, synthesis, and pharmacological profiling of a series of novel bicyclic and tricyclic N2‐alkyl‐indazole‐amide derivatives. This study identified a 3,4‐dihydropyrazino[1,2‐b]indazol‐1(2H)‐one derivative with potent serotonin 2A receptor antagonism, >100‐fold selectivity over other serotonin subtype receptors, and high affinity for the α₁ receptor. Moreover, upon local administration, this compound showed superior ocular hypotensive action in vivo relative to the clinically used reference compound timolol.     

Post-synthesis modifications of SBA-15 carbon replicas: Improving hydrogen storage by increasing microporous volume

SBA-15 carbon replicas were synthesized with a sucrose solution as carbon source, carrying out carbonization at two different temperatures (800 and 1000 °C). Carbon pyrolised at 800 °C showed higher BET surface area and was chosen for further post-synthesis activation treatments (physical via CO₂ or chemical via KOH), with the aim of improving hydrogen adsorption capacity. For comparison, an amorphous carbon was also synthesized, by direct carbonization of the carbon source, without any inorganic template: on this material a chemical activation was also performed. H₂ adsorption isotherms at the temperature of liquid nitrogen and sub-atmospheric pressure were measured. A linear correlation was found between hydrogen uptake and microporous volume of the different carbons, rather than with BET specific surface area. Surprisingly, the sample prepared in the absence of inorganic template resulted the most effective one.     

Some new models of software testing with performance comparisons

Two models of software testing, developed previously by T. Downs (see IEEE Trans. Software Eng., vol.SE-11, no.4, p.375-86, 1985, and IEEE Trans. Software Eng., vol.SE-12, no.9, p.979-87, 1986), are generalized to incorporate a greater degree of realism. This generalization leads to three new models. A fourth model, which has been developed using a different line of reasoning, is also presented. The performance of these models as reliability predictors is assessed by applying them to 16 sets of failure data collected from various software development projects. Comparisons of performance are made with the two earlier models and with two variants of the model of B. Littlewood and L. Verall (1973). Three distinct measurers of performance are employed. The performance of the new models is generally superior to that of the older models with one model showing outstanding performance under all three measures