Rare case of magnetic Ag3+^{3+} ion: double perovskite Cs2_{2}KAgF6_{6}

Normally $4d$ or $5d$ transition metals are in a low-spin state. Here using first-principles calculations, we report on a rare case of a high-spin $S$=1 magnetic state for the Ag$^{3+}$ ion in the double perovskite Cs$_{2}$KAgF$_{6}$. We also explored a possibility of a conventional low-spin $S$=0 ground state and find an associated tetragonal distortion to be 0.29 {\AA}. However, the lattice elastic energy cost and the Hund exchange loss exceed the e$_{g}$ crystal-field energy gain, thus making the low-spin tetragonal structure less favorable than the high-spin cubic structure. We conclude that the compact perovskite structure of Cs$_{2}$KAgF$_{6}$ is an important factor in stabilizing the unusual high-spin ground state of Ag$^{3+}$.Comment: 6 pages, 6 figures, accepted for publication in PR

Computation-Performance Optimization of Convolutional Neural Networks with Redundant Kernel Removal

Deep Convolutional Neural Networks (CNNs) are widely employed in modern computer vision algorithms, where the input image is convolved iteratively by many kernels to extract the knowledge behind it. However, with the depth of convolutional layers getting deeper and deeper in recent years, the enormous computational complexity makes it difficult to be deployed on embedded systems with limited hardware resources. In this paper, we propose two computation-performance optimization methods to reduce the redundant convolution kernels of a CNN with performance and architecture constraints, and apply it to a network for super resolution (SR). Using PSNR drop compared to the original network as the performance criterion, our method can get the optimal PSNR under a certain computation budget constraint. On the other hand, our method is also capable of minimizing the computation required under a given PSNR drop.Comment: This paper was accepted by 2018 The International Symposium on Circuits and Systems (ISCAS

Vaccine Adjuvant Delivery Systems Constructed Using Biocompatible Nanoparticles Formed through Self-Assembly of Small Molecules

Subunit vaccines are playing a critical role in controlling numerous diseases and attracting more and more research interests due to their numerous advantages over conventional whole microbe-based vaccines. However, subunit vaccines are weak immunogens and thus have limited capacity in eliciting the humoral and cellular immunity against pathogens. Recently, nanoparticles (NPs) formed with certain small molecules through self-assembly have been employed as an effective carrier for subunit vaccines to play roles of adjuvant, delivery and stabilization of antigens, thus engendering a vaccine adjuvant-delivery system (VADS), which shows promises to overcome the hurdles in developing subunit vaccines. In particular, the small molecule-self-assembled NPs as a VADS can not only deliver vaccine ingredients to immune cells but also influence the immunoresponse toward a Th1 (type 1 T helper cell) and Th2 balanced pathway to establish both humoral and cellular immunity. This chapter describes the innovative VADSs based on the small molecule-self-assembled NPs, such as metal NPs (mNPs), emulsions, liposomes, and ISCOMs, which are elaborately designed for the development of subunit vaccines

Vaccines Developed for Cancer Immunotherapy

Vaccines have been successfully used for prophylaxis of infectious diseases for a long time and in the last decades have inspired researchers to make products with similar immunological mechanisms for cancer immunotherapy, which has been developed rapidly into clinical applications and has shown remarkable therapeutic efficacy, as exemplified by chimeric Ag receptor T cell (CAR-T cell) and immune checkpoint inhibitor-based therapies which can efficiently strengthen the body’s immune system to fight against cancer, but they are also expensive. Therefore, encouraged by recent success of cancer immunotherapy, scientists are actively developing the low-cost tumor Ag-based vaccines, which, however, usually exhibit weak immunostimulating effects and, therefore, are often formulated with nanoparticulate carriers to form a vaccine adjuvant-delivery system (VADS), which can not only enhance the efficacy but also mitigate the off-target toxicity associated with conventional anticancer vaccines. These nanoparticulate carrier-based VADSs have demonstrated multiple functions, such as targetedly triggering Ag-presenting cells, reeducating tumor-associated macrophages (TAM) to function as tumor suppressor agent, and eliciting robust cytotoxic T lymphocytes (CTLs) to kill tumor cells. This chapter introduces multifunctional VADS that have been engineered with nanoparticulate carriers, including polymeric-, lipid-, metallic-, and cell-based nanoparticles, and used as an alternative to the existent tools for cancer immunotherapy

Can Social Exchange Theory Explain Individual Knowledge-Sharing Behavior? A Meta-Analysis

Motivating people to contribute knowledge has become an important research topic and a major challenge for organizations. In order to promote knowledge-sharing, managers need to understand the mechanism that drives individuals to contribute their valuable knowledge. Several theories have been applied to study knowledge-sharing behavior. However, the research settings and findings are often inconsistent. In this study, we use the social exchange theory as our base to develop an extended model that includes IT support and organizational type as moderators. A meta-analysis on 29 reported studies was conducted to examine how different factors in the social exchange theory affect knowledge-sharing behavior. The findings confirm that the social exchange theory plays an important role underlying individuals’ knowledge-sharing behavior. The results also demonstrate that social interaction and trust derived from the social exchange theory and moderated by IT contextual factors can predict individual’s knowledge-sharing behavior