Environmental Control of Triplet Emission in Donor–Bridge–Acceptor Organometallics

Carbene‐metal‐amides (CMAs) are a promising family of donor–bridge–acceptor molecular charge‐transfer (CT) emitters for organic light‐emitting diodes. A universal approach is demonstrated to tune the energy of their CT emission. A blueshift of up to 210 meV is achievable in solid state via dilution in a polar host matrix. The origin of this shift has two components: constraint of thermally‐activated triplet diffusion, and electrostatic interactions between guest and polar host. This allows the emission of mid‐green CMA archetypes to be tuned to sky blue without chemical modifications. Monte‐Carlo simulations based on a Marcus‐type transfer integral successfully reproduce the concentration‐ and temperature‐dependent triplet diffusion process, revealing a substantial shift in the ensemble density of states in polar hosts. In gold‐bridged CMAs, this shift does not lead to a significant change in luminescence lifetime, thermal activation energy, reorganization energy, or intersystem crossing rate. These discoveries offer new insight into coupling between the singlet and triplet manifolds in CMA materials, revealing a dominant interaction between states of CT character. The same approach is employed using materials which have been chemically modified to alter the energy of their CT state directly, shifting the emission of sky‐blue chromophores into the practical blue range.     

Indoor levels of volatile organic compounds at Florentine museum environments in Italy

Indoor Air Quality monitoring in cultural institutions is of particular concern to protect these places and the cultural heritage content. An indoor monitoring campaign was performed in three museums in Florence (Italy) to determine the occurrence and levels of volatile organic compounds (VOCs). VOCs of interest included BTEX (benzene, toluene, ethylbenzene, xylenes), terpenes, aldehydes, organic acids, and cyclic volatile methyl siloxanes (cVMS). The most abundant VOCs in all samples analyzed were BTEX, which were strictly related to the traffic source, followed by siloxanes and terpenes. Among BTEX, toluene was always the most abundant followed by xylenes, ethylbenzene, and benzene. cVMS in exhibition rooms with the presence of visitors showed higher values compared to samples collected when the museums were closed. Terpenes showed not only the influence of vegetation-biogenic sources surrounding a museum but could also be related to the wood used for the construction of showcases and furniture and the use of cleaning products. Data obtained also showed the presence of organic acids and aldehydes whose source can be traced back to exhibits themselves and wood-based furniture. Assessing the levels of organic acids in museums is important because, over time, it can cause deterioration of the artifacts.     

Serum Amyloid A Receptor Blockade and Incorporation into High-Density Lipoprotein Modulates Its Pro-Inflammatory and Pro-Thrombotic Activities on Vascular Endothelial Cells

The acute phase protein serum amyloid A (SAA), a marker of inflammation, induces expression of pro-inflammatory and pro-thrombotic mediators including ICAM-1, VCAM-1, IL-6, IL-8, MCP-1 and tissue factor (TF) in both monocytes/macrophages and endothelial cells, and induces endothelial dysfunction—a precursor to atherosclerosis. In this study, we determined the effect of pharmacological inhibition of known SAA receptors on pro-inflammatory and pro-thrombotic activities of SAA in human carotid artery endothelial cells (HCtAEC). HCtAEC were pre-treated with inhibitors of formyl peptide receptor-like-1 (FPRL-1), WRW4; receptor for advanced glycation-endproducts (RAGE), (endogenous secretory RAGE; esRAGE) and toll-like receptors-2/4 (TLR2/4) (OxPapC), before stimulation by added SAA. Inhibitor activity was also compared to high-density lipoprotein (HDL), a known inhibitor of SAA-induced effects on endothelial cells. SAA significantly increased gene expression of TF, NFκB and TNF and protein levels of TF and VEGF in HCtAEC. These effects were inhibited to variable extents by WRW4, esRAGE and OxPapC either alone or in combination, suggesting involvement of endothelial cell SAA receptors in pro-atherogenic gene expression. In contrast, HDL consistently showed the greatest inhibitory action, and often abrogated SAA-mediated responses. Increasing HDL levels relative to circulating free SAA may prevent SAA-mediated endothelial dysfunction and ameliorate atherogenesis.     

A Regression-Based Calibration Method for Agent-Based Models

Computational Economics - Because of their complexity, taking agent-based models to the data is still an unresolved issue. In this paper we propose a method to calibrate the model parameters on...     

Efficiency analysis of information technology and online social networks management: An integrated DEA-model assessment

This paper analyses the relationship between productive efficiency and online-social-networks (OSN) in Spanish telecommunications firms. A data-envelopment-analysis (DEA) is used and several indicators of business “social Media” activities are incorporated. A super-efficiency analysis and bootstrapping techniques are performed to increase the model's robustness and accuracy. Then, a logistic regression model is applied to characterise factors and drivers of good performance in OSN. Results reveal the company's ability to absorb and utilise OSNs as a key factor in improving the productive efficiency. This paper presents a model for assessing the strategic performance of the presence and activity in OSN.     

The public health approach to youth violence and child maltreatment prevention at the Centers for Disease Control and Prevention.

Millions of people in the United States suffer the consequences of violence, including physical injuries, psychological trauma, and death. Solutions to violence have traditionally been reactive. Through the lens of the public health perspective, the Centers for Disease Control and Prevention (CDC) views violence as predictable based on various contributing factors, and thus as preventable. Within CDC, the Division of Violence Prevention (DVP) leads efforts to prevent injury, death, and disability, and to reduce the suffering and medical costs caused by violence. DVP employs a multidisciplinary, public health approach to identify factors associated with violence, and to develop, evaluate, and disseminate preventive interventions. Psychology is one discipline that has contributed to our approach. The authors present a series of violence prevention initiatives funded by the CDC that are framed within a public health perspective, with attention to the contributions of psychology to youth violence and child maltreatment prevention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cesium-137 contamination of soils in settlements of Leningrad oblast and assessment of data accumulated after the Chernobyl accident

The results of works performed in 2007 and 2008 to determine the contamination density (CD) of soil with ¹³⁷Cs and its depth distribution in 45 settlements of the Volosovo and Kingisepp raions of Leningrad oblast, affected by the Chernobyl accident, are reported. With the lognormal distribution of CD values assumed, the confidence ranges for the CD values averaged for specific settlements were estimated on the basis of the results of the above-mentioned works and of the whole set of data accumulated by now. The shortcomings of the Methodical Recommendations of 1990 as applied to the contamination conditions characteristic of Leningrad oblast are noted. In 35 of the 45 settlements surveyed, the volume of data accumulated by now is insufficient for making substantiated management and legal decisions. One of possible ways to make the studies less labor-consuming within the framework of the statistical model used is discussed.     

Proportional Sampling in Life Length Studies

In studying electron tube life, measuring the life of a tube in service in a system whose age is T amounts to lifelength proportional sampling. The problems of estimating mean life from such data are considered for finite T and for “equilibrium” (large T). Several variations on the straight-forward life-biased sampling plan which are avilable to the experimenter are mentioned and conditions are found under which these other sampling schemes would be better than the life-proportional scheme. Particular attention is paid to the gamma and Weibull families of distributions. Other applications of these results are discussed.