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81.
Freeman Dyson has questioned whether any conceivable experiment in the real universe can detect a single graviton. If not, is it meaningful to talk about gravitons as physical entities? We attempt to answer Dyson’s question and find it is possible concoct an idealized thought experiment capable of detecting one graviton; however, when anything remotely resembling realistic physics is taken into account, detection becomes impossible, indicating that Dyson’s conjecture is very likely true. We also point out several mistakes in the literature dealing with graviton detection and production. 相似文献
82.
83.
Far‐Red and Near‐IR AIE‐Active Fluorescent Organic Nanoprobes with Enhanced Tumor‐Targeting Efficacy: Shape‐Specific Effects
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Andong Shao Prof. Dr. Yongshu Xie Shaojia Zhu Dr. Zhiqian Guo Shiqin Zhu Dr. Jin Guo Prof. Dr. Ping Shi Prof. Dr. Tony D. James Prof. Dr. He Tian Prof. Dr. Wei‐Hong Zhu 《Angewandte Chemie (International ed. in English)》2015,54(25):7275-7280
The rational design of high‐performance fluorescent materials for cancer targeting in vivo is still challenging. A unique molecular design strategy is presented that involves tailoring aggregation‐induced emission (AIE)‐active organic molecules to realize preferable far‐red and NIR fluorescence, well‐controlled morphology (from rod‐like to spherical), and also tumor‐targeted bioimaging. The shape‐tailored organic quinoline–malononitrile (QM) nanoprobes are biocompatible and highly desirable for cell‐tracking applications. Impressively, the spherical shape of QM‐5 nanoaggregates exhibits excellent tumor‐targeted bioimaging performance after intravenously injection into mice, but not the rod‐like aggregates of QM‐2. 相似文献
84.
Dr. George N. Khairallah Dr. Alan T. Maccarone Dr. Huong T. Pham Timothy M. Benton Dr. Tony Ly Dr. Gabriel da Silva Prof. Stephen J. Blanksby Prof. Richard A. J. O'Hair 《Angewandte Chemie (International ed. in English)》2015,54(44):12947-12951
Although the deleterious effects of ozone on the human respiratory system are well‐known, many of the precise chemical mechanisms that both cause damage and afford protection in the pulmonary epithelial lining fluid are poorly understood. As a key first step to elucidating the intrinsic reactivity of ozone with proteins, its reactions with deprotonated cysteine [Cys?H]? are examined in the gas phase. Reaction proceeds at near the collision limit to give a rich set of products including 1) sequential oxygen atom abstraction reactions to yield cysteine sulfenate, sulfinate and sulfonate anions, and significantly 2) sulfenate radical anions formed by ejection of a hydroperoxy radical. The free‐radical pathway occurs only when both thiol and carboxylate moieties are available, implicating electron‐transfer as a key step in this reaction. This novel and facile reaction is also observed in small cys‐containing peptides indicating a possible role for this chemistry in protein ozonolysis. 相似文献
85.
Dr. Sabine Lennarz MSc Therese Christine Alich Dr. Tony Kelly Dr. Michael Blind Prof. Dr. Heinz Beck Prof. Dr. Günter Mayer 《Angewandte Chemie (International ed. in English)》2015,54(18):5369-5373
Cellular behavior is orchestrated by the complex interactions of a myriad of intracellular signal transduction pathways. To understand and investigate the role of individual components in such signaling networks, the availability of specific inhibitors is of paramount importance. We report the generation and validation of a novel variant of an RNA aptamer that selectively inhibits the mitogen‐activated kinase pathway in neurons. We demonstrate that the aptamer retains function under intracellular conditions and that application of the aptamer through the patch‐clamp pipette efficiently inhibits mitogen‐activated kinase‐dependent synaptic plasticity. This approach introduces synthetic aptamers as generic tools, readily applicable to inhibit different components of intraneuronal signaling networks with utmost specificity. 相似文献
86.
The covalent boron–diol interaction enables elaborate design of boronic acid‐based saccharide sensors. Over the last decade, this research topic has been well developed thanks to the integration of boronic acid chemistry with a range of techniques, including supramolecular chemistry, materials chemistry, surface modification, and nanotechnology. New sensing strategies and platforms have been introduced and remarkable progress has been achieved to fully utilize the unique property of boron–diol interaction and to improve the binding affinity towards different targets, especially under physiological conditions. In this review, the latest progress over the past 30 months (from late 2012 to early 2015) is highlighted and discussed to shed light on this versatile and promising platform for saccharide sensing. 相似文献
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88.
We consider random subgraphs of a fixed graph with large minimum degree. We fix a positive integer k and let Gk be the random subgraph where each independently chooses k random neighbors, making kn edges in all. When the minimum degree then Gk is k‐connected w.h.p. for ; Hamiltonian for k sufficiently large. When , then Gk has a cycle of length for . By w.h.p. we mean that the probability of non‐occurrence can be bounded by a function (or ) where . © 2016 Wiley Periodicals, Inc. Random Struct. Alg., 50, 143–157, 2017 相似文献
89.
John R. Britnell Neil Saunders Tony Skyner 《Journal of Pure and Applied Algebra》2017,221(11):2647-2665
A finite group G is exceptional if it has a quotient Q whose minimal faithful permutation degree is greater than that of G. We say that Q is a distinguished quotient.The smallest examples of exceptional p-groups have order . For an odd prime p, we classify all pairs where G has order and Q is a distinguished quotient. (The case has already been treated by Easdown and Praeger.) We establish the striking asymptotic result that as p increases, the proportion of groups of order with at least one exceptional quotient tends to 1/2. 相似文献
90.
During the last decade numerous protocols have been published using the method of ball milling for synthesis all over the field of organic chemistry. However, compared to other methods leaving their marks on the road to sustainable synthesis (e.g. microwave, ultrasound, ionic liquids) chemistry in ball mills is rather underrepresented in the knowledge of organic chemists. Especially, in the last three years the interest in this technique raised continuously, culminating in several high-quality synthetic procedures covering the whole range of organic synthesis. Thus, the present tutorial review will be focused on the highlights using this method of energy transfer and energy dissipation. The central aim is to motivate researchers to take notice of ball mills as chemical reactors, implementing this technique in everyday laboratory use and thus, pave the ground for future activities in this interdisciplinary field of research. 相似文献