ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInitiation of methyl methacrylate polymerization by the non-volatile products of a methyl methacrylate plasma. 1. Polymerization kineticsCharles W. Paul, Alexis T. Bell, and David S. SoongCite this: Macromolecules 1985, 18, 11, 2312–2318Publication Date (Print):November 1, 1985Publication History Published online1 May 2002Published inissue 1 November 1985https://doi.org/10.1021/ma00153a046Request reuse permissionsArticle Views134Altmetric-Citations14LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (880 KB) Get e-Alertsclose Get e-Alerts
Materials synthesis is a critical step in the development of energy storage technologies, from the first synthesis of newly predicted materials to the optimization of key properties for established materials. While the synthesis of solid-state materials has traditionally relied on intuition-driven trial-and-error, computational approaches are now emerging to accelerate the identification of improved synthesis recipes. In this Perspective, we explore these techniques and focus on their ability to guide precursor selection for solid-state synthesis. The applicability of each method is discussed in the context of materials for batteries, including Li-ion cathodes and solid electrolytes for all-solid-state batteries. Our analysis showcases the effectiveness of these computational methods while also highlighting their limitations. Based on these findings, we provide an outlook on future developments that can address existing limitations and make progress toward synthesis-by-design for battery materials.
We report stereodivergent allylic substitution reactions of allylic esters with prochiral enolates derived from azaaryl acetamides and acetates to form products from addition of the enolates at the most substituted carbon of an allyl moiety with two catalysts, a chiral metallacyclic iridium complex and a chiral bisphosphine-ligated copper(I) complex, which individually control the configuration of the electrophilic and nucleophilic carbon atoms, respectively. By simple permutations of enantiomers of the two catalysts, all four stereoisomers of products containing two stereogenic centers were synthesized individually with high diastereoselectivity and enantioselectivity. A variety of azaaryl acetamides and acetates bearing pyridyl, benzothiazolyl, benzoxazolyl, pyrazinyl, quinolinyl and isoquinolinyl moieties were all found to be suitable for this transformation.
At the intersection of telerobotics, computer networking and human social interaction we have chosen to explore an area we identify as personal tele-embodiment. At the core of this research is an emphasis on the individual person rather than the intricate complexities of the machine. While the mechanical elements of our system are essential to its over-all functionality, our research is driven solely by the study and understanding of the social and psychological aspects of extended human-human interactions rather than the latest techno-gadgetry. In this paper we emphasize the importance of the human component and describe the development of one such simple, inexpensive, Internet-controlled, untethered telerobot or PRoP (personal roving presence) that provides several fundamental elements of personal tele-embodiment.
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Recent proposals suggest that sleep may be a factor associated with accumulation of two core pathological features of Alzheimer's disease (AD): tau and β-amyloid (Aβ). Here we combined PET measures of Aβ and tau, electroencephalogram sleep recordings, and retrospective sleep evaluations to investigate the potential utility of sleep measures in predicting <i>in vivo</i> AD pathology in male and female older adults. Regression analyses revealed that the severity of impaired slow oscillation-sleep spindle coupling predicted greater medial temporal lobe tau burden. Aβ burden was not associated with coupling impairment but instead predicted the diminished amplitude of <1 Hz slow-wave-activity, results that were statistically dissociable from each other. Additionally, comparisons of AD pathology and retrospective, self-reported changes in sleep duration demonstrated that changes in sleep across the lifespan can predict late-life Aβ and tau burden. Thus, quantitative and qualitative features of human sleep represent potential noninvasive, cost-effective, and scalable biomarkers (current and future forecasting) of AD pathology, and carry both therapeutic and public health implications.<b>SIGNIFICANCE STATEMENT</b> Several studies have linked sleep disruption to the progression of Alzheimer's disease (AD). Tau and β-amyloid (Aβ), the primary pathological features of AD, are associated with both objective and subjective changes in sleep. However, it remains unknown whether late life tau and Aβ burden are associated with distinct impairments in sleep physiology or changes in sleep across the lifespan. Using polysomnography, retrospective questionnaires, and tau- and Aβ-specific PET, the present study reveals human sleep signatures that dissociably predict levels of brain tau and Aβ in older adults. These results suggest that a night of polysomnography may aid in evaluating tau and Aβ burden, and that treating sleep deficiencies within decade-specific time windows may serve in delaying AD progression.
We present a new type of strange attractors generated by an odd-symmetric three-dimensional vector field with a saddle-focus having two homoclinic orbits at the origin. This type of attractors is intimately related to the double scroll. We present the mathematical properties which prove rigorously the chaotic nature of this strange attractor to be different from that of a Lorenz-type attractor or a quasiattractor. In particular, we proved that for certain nonempty intervals of parameters, our two-dimensional map has a strange attractor with no stable orbits. Unlike other known attractors, this strange attractor contains not only a Cantor set structure of hyperbolic points typical of horseshoe maps, but also unstable points (i.e., stable in reverse time). This implies that the points from the stable manifolds of the hyperbolic points must necessarily attract the unstable points.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
