Daqiang Li

© 2015 American Chemical Society.Near-infrared dye-sensitized upconversion nanoparticles can broaden the absorption range and boost upconversion efficiency of UCNPs. Here, we achieved significantly enhanced upconversion luminescence in dye-sensitized core/active shell UCNPs via the doping of ytterbium ions in the UCNP shell, which bridged the energy transfer from the dye to the UCNP core. As a result, we synergized the two most practical upconversion booster effectors to amplify upconversion efficiency. We demonstrated two biomedical applications using these UCNPs. By using dye-sensitized core/active shell UCNP embedded poly polymer implantable systems, we successfully shifted the optogenetic neuron excitation window to a biocompatible and deep tissue penetrable 800 nm wavelength. Furthermore, UCNPs were water-solubilized with Pluronic F127 with high upconversion efficiency and can be imaged in a mouse model.

© 2015 Macmillan Publishers Limited All rights reserved. Genome-wide gene expression measurements have enabled comprehensive studies that integrate the changes of gene expression and phenotypic information to uncover their novel associations. Here we reported the association analysis between psychophysical phenotypes and genome-wide gene expression changes in human adaptation to one of the most extreme climates on Earth, the Antarctic Dome Argus. Dome A is the highest ice feature in Antarctica, and may be the coldest, driest and windiest location on earth. It is considered unapproachable due to its hostile environment. In 2007, a Chinese team of 17 male explorers made the expedition to Dome A for scientific investigation. Overall, 133 psychophysical phenotypes were recorded, and genome-wide gene expression profiles from the blood samples of the explorers were measured before their departure and upon their arrival at Dome A. We found that mood disturbances, including tension, depression, anger and fatigue, had a strong, positive, linear relationship with the level of a male sex hormone, testosterone, using the Pearson correlation coefficient analysis. We also demonstrated that significantly lowest-level Gene Ontology groups in changes of gene expression in blood cells with erythrocyte removal were consistent with the adaptation of the psychophysical characteristics. Interestingly, we discovered a list of genes that were strongly related to significant phenotypes using phenotype and gene expression PCC analysis. Importantly, among the 70 genes that were identified, most were significantly related to mood disturbances, where 42 genes have been reported in the literature mining, suggesting that the other 28 genes were likely novel genes involved in the mood disturbance mechanism. Taken together, our association analysis provides a reliable method to uncover novel genes and mechanisms related to phenotypes, although further studies are needed.

Is the statue made of copper identical with the piece of copper from which it is made? This question was argued for years since Allan Gibbard published Contingent Identity in 1975. Before arguing for or against identity, I try to clarify different usages of the word “identity” and the conditions under which Leibniz’s Law is effective. In our language, there are four concepts of identity, and Leibniz’s Law works differently in each case. Both monist and pluralists fail to distinguish the four concepts. However, monist could be right.

This article focuses on several important but obscure concepts in Tractatus Logico-Philosophicus. In order to clarify the concept of “object”, I compare it with “atom”. The analysis of the two concepts explains two important questions which have confused Wittgenstein’s reviewers for long: why is the world not the totality of things? Is object substance? “Logical space” is an important concept in Tractatus Logico-Philosophicus, although it only appears several times. If a proposition serves as the coordinates in the logical space, what are the coordinate axes? Is a possible world a point in the logical space, or a set of points in it? Based on symbolic transformations, I suggest that possible worlds serve as coordinate axes in the logical space. The concept of “possible worlds” contradicts with “necessity”. In Wittgenstein’s theory, all possible worlds are “accessible” to one another. This is why Wittgenstein fails to cope with the conflict between “possibility” and “necessity”.