Electromagnetic emissions from the IC packaging

The EMC and EMI of the IC packaging are becoming increasingly important to modern electronics. Its EMC, SI, and PI have been broadly attested. But electromagnetic radiations from IC packaging and the corresponding EMI were seldom studied. In this paper, the fundamental principles and properties of the electromagnetic radiations caused by vias and traces in IC packagings are carefully investigated. Various radiation mechanisms are analyzed for different representative scenarios. Numerical simulations are employed to support the analyzing results. © 2012 IEEE.published_or_final_versio

Electromagnetic emissions from the IC packaging

The EMC and EMI of the IC packaging are becoming increasingly important to modern electronics. Its EMC, SI, and PI have been broadly attested. But electromagnetic radiations from IC packaging and the corresponding EMI were seldom studied. In this paper, the fundamental principles and properties of the electromagnetic radiations caused by vias and traces in IC packagings are carefully investigated. Various radiation mechanisms are analyzed for different representative scenarios. Numerical simulations are employed to support the analyzing results. © 2012 IEEE.published_or_final_versio

Adaptação do Questionário de Autonomia nos Adolescentes (QAA) para a língua portuguesa

O presente estudo tem como objectivo principal apresentar a versão portuguesa do Questionário de Autonomia nos Adolescentes, traduzido e adaptado a partir do Adolescent Autonomy Questionnaire (Noom, 1999). De forma a observar as qualidades psicométricas da versão portuguesa procedeu-se à análise da estrutura factorial, análise da fidelidade, análise da sensibilidade e correlações inter- -factores. Os resultados obtidos com uma amostra de 171 adolescentes indicaram, através de análise factorial confirmatória, que o modelo original constituído por três dimensões não se revelou adequado à estrutura correlacional observada. Neste sentido, recorreu-se a uma análise exploratória que reproduziu uma estrutura composta por quatro factores – Auto-determinação; Independência; Autonomia cognitiva e Autonomia emocional. Em termos gerais, observaram-se indícios favoráveis à adequabilidade da presente versão do instrumento para a população adolescente portuguesa em contexto escolar. As diferenças observadas entre os participantes em função da idade (14-16 anos vs. 17-19 anos) são consistentes com os resultados obtidos nos estudos do instrumento original, fornecendo evidências adicionais favoráveis à validade da versão portuguesa.ABSTRACT: The present study aims to adapt and translate the Adolescent Autonomy Questionnaire (Noom, 1999) for the Portuguese context. In order to observe the psychometric qualities of the Portuguese version, the factorial structure, reliability, sensibility and inter-factor correlations were analyzed. Confirmatory factor analysis with a sample of 171 adolescents revealed that the original tridimensional model was not adequate to the observed correlacional structure. Subsequent exploratory factor analysis yielded a structure with four factors – Self-determination, Independence, Cognitive autonomy and Emotional Autonomy. Concerning the psychometric qualities, analysis provided evidences favorable to the suitability of the present version of the questionnaire for the Portuguese adolescent population in educational context. The differences observed between the participants regarding their age (14-16 years vs. 17-19 years) are consistent with the results found in the studies of the original questionnaire, providing additional evidences favorable to the validity of the Portuguese version

Transcriptome-Guided Functional Analyses Reveal Novel Biological Properties and Regulatory Hierarchy of Human Embryonic Stem Cell-Derived Ventricular Cardiomyocytes Crucial for Maturation

Human (h) embryonic stem cells (ESC) represent an unlimited source of cardiomyocytes (CMs); however, these differentiated cells are immature. Thus far, gene profiling studies have been performed with non-purified or non-chamber specific CMs. Here we took a combinatorial approach of using systems biology to guide functional discoveries of novel biological properties of purified hESC-derived ventricular (V) CMs. We profiled the transcriptomes of hESCs, hESC-, fetal (hF) and adult (hA) VCMs, and showed that hESC-VCMs displayed a unique transcriptomic signature. Not only did a detailed comparison between hESC-VCMs and hF-VCMs confirm known expression changes in metabolic and contractile genes, it further revealed novel differences in genes associated with reactive oxygen species (ROS) metabolism, migration and cell cycle, as well as potassium and calcium ion transport. Following these guides, we functionally confirmed that hESC-VCMs expressed IKATP with immature properties, and were accordingly vulnerable to hypoxia/reoxygenation-induced apoptosis. For mechanistic insights, our coexpression and promoter analyses uncovered a novel transcriptional hierarchy involving select transcription factors (GATA4, HAND1, NKX2.5, PPARGC1A and TCF8), and genes involved in contraction, calcium homeostasis and metabolism. These data highlight novel expression and functional differences between hESC-VCMs and their fetal counterparts, and offer insights into the underlying cell developmental state. These findings may lead to mechanism-based methods for in vitro driven maturation. © 2013 Poon et al.published_or_final_versio

Steam reforming on transition-metal carbides from density-functional theory

A screening study of the steam reforming reaction (CH_4 + H_2O -> CO + 3H_2) on early transition-metal carbides (TMC's) is performed by means of density-functional theory calculations. The set of considered surfaces includes the alpha-Mo_2C(100) surfaces, the low-index (111) and (100) surfaces of TiC, VC, and delta-MoC, and the oxygenated alpha-Mo_2C(100) and TMC(111) surfaces. It is found that carbides provide a wide spectrum of reactivities towards the steam reforming reaction, from too reactive via suitable to too inert. The reactivity is discussed in terms of the electronic structure of the clean surfaces. Two surfaces, the delta-MoC(100) and the oxygen passivated alpha-Mo_2C(100) surfaces, are identified as promising steam reforming catalysts. These findings suggest that carbides provide a playground for reactivity tuning, comparable to the one for pure metals.Comment: 6 pages, 4 figure

Gut microbiota-derived propionate reduces cancer cell proliferation in the liver

Peer reviewedPublisher PD

Monodisperse Hollow Tricolor Pigment Particles for Electronic Paper

A general approach has been designed to blue, green, and red pigments by metal ions doping hollow TiO 2. The reaction involves initial formation of PS at TiO2 core–shell nanoparticles via a mixed-solvent method, and then mixing with metal ions solution containing PEG, followed calcining in the atmosphere. The as-prepared hollow pigments exhibit uniform size, bright color, and tunable density, which are fit for electronic paper display

Discrete approaches to quantum gravity in four dimensions

The construction of a consistent theory of quantum gravity is a problem in theoretical physics that has so far defied all attempts at resolution. One ansatz to try to obtain a non-trivial quantum theory proceeds via a discretization of space-time and the Einstein action. I review here three major areas of research: gauge-theoretic approaches, both in a path-integral and a Hamiltonian formulation, quantum Regge calculus, and the method of dynamical triangulations, confining attention to work that is strictly four-dimensional, strictly discrete, and strictly quantum in nature.Comment: 33 pages, invited contribution to Living Reviews in Relativity; the author welcomes any comments and suggestion

Synthesis and Application of Carbon–Iron Oxide Microspheres’ Black Pigments in Electrophoretic Displays

Carbon–iron oxide microspheres’ black pigments (CIOMBs) had been prepared via ultrasonic spray pyrolysis of aqueous solutions containing ferrous chloride and glucose. Due to the presence of carbon, CIOMBs not only exhibited remarkably acid resistance, but also could be well dispersed in both polar solvents and nonpolar solvent. Finally, dispersions of hollow CIOMBs in tetrachloroethylene had successfully been applied in electrophoretic displays