No abstract

Most binary superlattices created using DNA functionalization or other approaches rely on particle size differences to achieve compositional order and structural diversity. Here we study two-dimensional (2D) assembly of DNAfunctionalized micron-sized particles (DFPs), and employ a strategy that leverages the tunable disparity in interparticle interactions, and thus enthalpic driving forces, to open new avenues for design of binary superlattices that do not rely on the ability to tune particle size (i.e., entropic driving forces). Our strategy employs tailored blends of complementary strands of ssDNA to control interparticle interactions between micron-sized silica particles in a binary mixture to create compositionally diverse 2D lattices. We show that the particle arrangement can be further controlled by changing the stoichiometry of the binary mixture in certain cases. With this approach, we demonstrate the ability to program the particle assembly into square, pentagonal, and hexagonal lattices. In addition, different particle types can be compositionally ordered in square checkerboard and hexagonal -alternating string, honeycomb, and Kagome arrangements. The field of DNA-mediated particle assembly has undergone remarkable progress over recent years (1), owing, at least in part, to its potential as a powerful platform for rational, bottomup design and engineering of complex materials, and motivated by recent successful translations into applications as diverse as sensing (2), photonics (3), and catalysis. The growing number of synthetic pathways and design strategies to fabricate DNA-functionalized particles (DFPs) has led to the development of a diverse palette of tailorable building blocks from which to choose, comprised of particles of a wide range of inorganic to organic compositions, a near continuum of particle sizes spanning nanometers to micrometers, precise DNA sequence control and thus tailorable hybridization, diverse chemistries for DNA grafting/association, and fine tunability of the grafting density. (4)(5)(6) Accompanying this expanding diversity of building blocks has been a parallel development of specific to generalized design principles that have begun to link molecular-scale DFP function with mechanisms of assembly and the resulting uni-or multi-modal crystalline structures.To this end, the growing combination of theory, simulations, and experiments, has helped to overcome some of the challenges in the field. For example, re-entrant melting strategies (7,8) have been successfully developed to alleviate the very narrow temperature ranges for efficient crystallization of DFPs.The most common route to induce attraction between DFPs, and thus program their assembly, leverages the direct or indirect (i.e., with additional DNA linker strand) hybridization of complementary DNA strands tethered separately to two types of particles. Under suitable conditions in such systems, particles with complementary DNA functionality (i.e., 'unlike' particles) form attractive contacts among multiple strands of h...

The Korean very-long-baseline interferometry (VLBI) network (KVN) and VLBI Exploration of Radio Astrometry (VERA) Array (KaVA) is the first international VLBI array dedicated to high-frequency (23–43 GHz bands) observations in East Asia. Here, we report the first imaging observations of three bright active galactic nuclei (AGNs) known for their complex morphologies: 4C 39.25, 3C 273, and M 87. This is one of the initial results of KaVA's early operation. Our KaVA images reveal extended outflows with complex substructures such as knots and limb brightening, in agreement with previous Very Long Baseline Array (VLBA) observations. Angular resolutions are better than 1.4 and 0.8 mas at 23 and 43 GHz, respectively. KaVA achieves a high dynamic range of ∼ 1000, more than three times the value achieved by VERA. We conclude that KaVA is a powerful array with a great potential for the study of AGN outflows, at least comparable to the best existing radio interferometric arrays.

The operating temperature of a battery strongly affects overall chemical reactions, ion transport, intercalation and deintercalation process, and consequently, efficiency, cycle life, and degradation of battery systems. Therefore, thermal management for battery systems should be optimally designed to secure a highly efficient and reliable operation of the battery systems, which requires characterization and analysis of heat generated during operation. In this paper, a thermal model that includes irreversible and reversible heat source terms is developed and then incorporated into a reduced-order electrochemical model (ROM). The model is validated against the heat generation rate of a large format pouch type lithium-ion battery measured by a developed calorimeter that enables the measurement of heat generation rate and entropy coefficient. The model is seen to be in good agreement with the measured heat generation rates up to 3C from −30 °C to 45 °C. The analysis includes the effects of C-rates and temperatures on the two heat source terms generated during charging and discharging.

No abstract

No abstract

Binary superlattices constructed from nano- or micron-sized colloidal particles have a wide variety of applications, including the design of advanced materials. Self-assembly of such crystals from their constituent colloids can be achieved in practice by, among other means, the functionalization of colloid surfaces with single-stranded DNA sequences. However, when driven by DNA, this assembly is traditionally premised on the pairwise interaction between a single DNA sequence and its complement, and often relies on particle size asymmetry to entropically control the crystalline arrangement of its constituents. The recently proposed "multi-flavoring" motif for DNA functionalization, wherein multiple distinct strands of DNA are grafted in different ratios to different colloids, can be used to experimentally realize a binary mixture in which all pairwise interactions are independently controllable. In this work, we use various computational methods, including molecular dynamics and Wang-Landau Monte Carlo simulations, to study a multi-flavored binary system of micron-sized DNA-functionalized particles modeled implicitly by Fermi-Jagla pairwise interactions. We show how self-assembly of such systems can be controlled in a purely enthalpic manner, and by tuning only the interactions between like particles, demonstrate assembly into various morphologies. Although polymorphism is present over a wide range of pairwise interaction strengths, we show that careful selection of interactions can lead to the generation of pure compositionally ordered crystals. Additionally, we show how the crystal composition changes with the like-pair interaction strengths, and how the solution stoichiometry affects the assembled structures.

Apoptosis signal-regulating kinase 1 (ASK1), a member of the MAP kinase kinase kinase, is activated by several death stimuli and is tightly regulated by several mechanisms such as interactions with regulatory proteins and post-translational modifications. Here, we report that dual-specificity phosphatase 13A (DUSP13A) functions as a novel regulator of ASK1. DUSP13A interacts with the N-terminal domain of ASK1 and induces ASK1-mediated apoptosis through the activation of caspase-3. DUSP13A enhances ASK1 kinase activity and thus its downstream factors. Small interfering RNA (siRNA) analyses show that knock-down of DUSP13A in human neuroblastoma SK-N-SH cells reduces ASK1 kinase activity. The phosphatase activity of DUSP13A is not required for the regulation of ASK1. This regulatory action of DSUP13 on ASK1 activity involves competition with Akt1, a negative regulator of ASK1, for binding to ASK1. Taken together, this study provides novel insights into the role of DUSP13A in the precise regulation of ASK1.